ci: run github actions on pull requests

Closes getodk#1315

.github/workflows/oidc-e2e.yml

@@ -1,13 +1,16 @@
 name: OIDC e2e tests
 
-on: push
+on:
+  push:
+  pull_request:
 
 env:
   DEBUG: pw:api
   ODK_PLAYWRIGHT_BROWSERS: chromium,firefox,webkit
 
 jobs:
   oidc-e2e-test:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 6
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest

.github/workflows/oidc-integration.yml

@@ -1,9 +1,12 @@
 name: OIDC integration tests
 
-on: push
+on:
+  push:
+  pull_request:
 
 jobs:
   oidc-integration-test:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 6
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest

.github/workflows/s3-e2e.yml

@@ -1,9 +1,12 @@
 name: S3 E2E Tests
 
-on: push
+on:
+  push:
+  pull_request:
 
 jobs:
   s3-e2e:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 15
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest

.github/workflows/soak-test.yml

@@ -1,9 +1,12 @@
 name: Soak Test
 
-on: push
+on:
+  push:
+  pull_request:
 
 jobs:
   soak-test:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 15
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest

.github/workflows/standard-e2e.yml

@@ -1,12 +1,15 @@
 name: Standard E2E Tests
 
-on: push
+on:
+  push:
+  pull_request:
 
 env:
   LOG_LEVEL: DEBUG
 
 jobs:
   standard-e2e:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 15
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest

.github/workflows/standard-suite.yml

@@ -1,9 +1,12 @@
 name: Full Standard Test Suite
 
-on: push
+on:
+  push:
+  pull_request:
 
 jobs:
   standard-tests:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     timeout-minutes: 20
     # TODO should we use the same container as circle & central?
     runs-on: ubuntu-latest