chore(sdk): Update mlflow version in sdk (#616)

# Description
This PR is the **first part** (1 out of 3) of a series of PRs to update
the version of Mlflow used by Merlin (to `1.26.1`*). These changes are:

1. Update the version of Mlflow used in the Merlin SDK and publish it to
PyPI
2. Update 
- the Merlin pyfunc server and batch predictor to use the updated Merlin
SDK version released in step 1 and publish them to PyPI
- the Merlin API server to ensure that requests sent to Mlflow reflect
the update API endpoint contracts
   - the Mlflow image so that it's built using version `1.26.1`
3. Update the default pyfunc server and batch predictor version in the
Merlin SDK and publish its new version to PyPI

I also made some minor refactoring to the requirements files so that
they are stored in a separate file and the reading of these files is
consistent with what is done in the batch predictor and pyfunc server
`setup.py` files.

*I've selected `1.26.1` because it's the latest version of Mlflow
available that is before Mlflow v2, that still allows `pandas==2.2.0` to
be installed (this is a hard requirement needed by the `arize` package).

# Modifications
- Update Mlflow version to `1.26.1` (and other dependencies) in the SDK
as well as observation publisher's requirements file since the unit
tests there import the SDK's requirements file's dependencies
- ~~Update unit tests to ensure that the updated `PythonModelContext`
from Mlflow is initialised with the required arguments~~ (will only be
needed for newer versions of Mlflow)

# Tests
<!-- Besides the existing / updated automated tests, what specific
scenarios should be tested? Consider the backward compatibility of the
changes, whether corner cases are covered, etc. Please describe the
tests and check the ones that have been completed. Eg:
- [x] Deploying new and existing standard models
- [ ] Deploying PyFunc models
-->

# Checklist
- [x] Added PR label
- [ ] Added unit test, integration, and/or e2e tests
- [x] Tested locally
- [ ] Updated documentation
- [ ] Update Swagger spec if the PR introduce API changes
- [ ] Regenerated Golang and Python client if the PR introduces API
changes

# Release Notes
<!--
Does this PR introduce a user-facing change?
If no, just write "NONE" in the release-note block below.
If yes, a release note is required. Enter your extended release note in
the block below.
If the PR requires additional action from users switching to the new
release, include the string "action required".

For more information about release notes, see kubernetes' guide here:
http://git.k8s.io/community/contributors/guide/release-notes.md
-->

```release-note
NONE
```

python/observation-publisher/requirements.txt

@@ -22,9 +22,9 @@ binaryornot==0.4.4
     # via cookiecutter
 blinker==1.7.0
     # via flask
-boto3==1.34.45
+boto3==1.35.39
     # via merlin-sdk
-botocore==1.34.45
+botocore==1.35.39
     # via
     #   boto3
     #   s3transfer
@@ -215,7 +215,7 @@ python-dateutil==2.8.2
     #   pandas
 python-slugify==8.0.4
     # via cookiecutter
-pytz==2024.1
+pytz==2022.7.1
     # via
     #   mlflow
     #   pandas

python/sdk/requirements.txt

@@ -0,0 +1,20 @@
+boto3>=1.35.39
+caraml-upi-protos>=0.3.1
+certifi>=2017.4.17
+Click>=7.0,<8.1.4
+cloudpickle==2.0.0  # used by mlflow
+cookiecutter>=1.7.2
+dataclasses-json>=0.5.2  # allow Flyte version 1.2.0 or above to import Merlin SDK
+docker<=6.1.3
+GitPython>=3.1.40
+google-cloud-storage>=1.19.0
+protobuf>=3.12.0,<5.0.0  # Determined by the mlflow dependency
+mlflow==1.26.1
+PyPrind>=2.11.2
+python_dateutil>=2.5.3
+PyYAML>=5.4
+six>=1.10
+urllib3>=1.26
+numpy<=1.23.5  # Temporary pin numpy due to https://numpy.org/doc/stable/release/1.20.0-notes.html#numpy-1-20-0-release-notes
+caraml-auth-google==0.0.0.post7
+pydantic==2.5.3

python/sdk/requirements_test.txt

@@ -0,0 +1,18 @@
+google-cloud-bigquery-storage>=0.7.0
+google-cloud-bigquery>=1.18.0
+joblib>=0.13.0,<1.2.0  # >=1.2.0 upon upgrade of kserve's version
+mypy>=0.812
+pytest-cov
+pytest-dependency
+pytest-xdist
+pytest
+recursive-diff>=1.0.0
+requests
+scikit-learn>=1.1.2
+types-python-dateutil
+types-PyYAML
+types-six
+types-protobuf
+urllib3-mock>=0.3.3
+xarray
+xgboost==1.6.2

python/sdk/setup.py

@@ -22,49 +22,11 @@
     "merlin.version", os.path.join("merlin", "version.py")
 ).VERSION
 
-REQUIRES = [
-    "boto3>=1.9.84",
-    "caraml-upi-protos>=0.3.1",
-    "certifi>=2017.4.17",
-    "Click>=7.0,<8.1.4",
-    "cloudpickle==2.0.0",  # used by mlflow
-    "cookiecutter>=1.7.2",
-    "dataclasses-json>=0.5.2",  # allow Flyte version 1.2.0 or above to import Merlin SDK
-    "docker<=6.1.3",
-    "GitPython>=3.1.40",
-    "google-cloud-storage>=1.19.0",
-    "protobuf>=3.12.0,<5.0.0",  # Determined by the mlflow dependency
-    "mlflow==1.26.1",
-    "PyPrind>=2.11.2",
-    "python_dateutil>=2.5.3",
-    "PyYAML>=5.4",
-    "six>=1.10",
-    "urllib3>=1.26",
-    "numpy<=1.23.5",  # Temporary pin numpy due to https://numpy.org/doc/stable/release/1.20.0-notes.html#numpy-1-20-0-release-notes
-    "caraml-auth-google==0.0.0.post7",
-    "pydantic==2.5.3"
-]
+with open("requirements.txt") as f:
+    REQUIRE = f.read().splitlines()
 
-TEST_REQUIRES = [
-    "google-cloud-bigquery-storage>=0.7.0",
-    "google-cloud-bigquery>=1.18.0",
-    "joblib>=0.13.0,<1.2.0",  # >=1.2.0 upon upgrade of kserve's version
-    "mypy>=0.812",
-    "pytest-cov",
-    "pytest-dependency",
-    "pytest-xdist",
-    "pytest",
-    "recursive-diff>=1.0.0",
-    "requests",
-    "scikit-learn>=1.1.2",
-    "types-python-dateutil",
-    "types-PyYAML",
-    "types-six",
-    "types-protobuf",
-    "urllib3-mock>=0.3.3",
-    "xarray",
-    "xgboost==1.6.2",
-]
+with open("requirements_test.txt") as f:
+    TESTS_REQUIRE = f.read().splitlines()
 
 setup(
     name="merlin-sdk",
@@ -75,10 +37,10 @@
     packages=find_packages(),
     package_data={"merlin": ["docker/pyfunc.Dockerfile", "docker/standard.Dockerfile"]},
     zip_safe=True,
-    install_requires=REQUIRES,
+    install_requires=REQUIRE,
     setup_requires=["setuptools_scm"],
-    tests_require=TEST_REQUIRES,
-    extras_require={"test": TEST_REQUIRES},
+    tests_require=TESTS_REQUIRE,
+    extras_require={"test": TESTS_REQUIRE},
     python_requires=">=3.8,<3.11",
     long_description=open("README.md").read(),
     long_description_content_type="text/markdown",