Bump bibtexparser from 2.0.0b6 to 2.0.0b7

Bumps [bibtexparser](https://github.com/sciunto-org/python-bibtexparser) from 2.0.0b6 to 2.0.0b7.
- [Release notes](https://github.com/sciunto-org/python-bibtexparser/releases)
- [Changelog](https://github.com/sciunto-org/python-bibtexparser/blob/main/CHANGELOG)
- [Commits](sciunto-org/python-bibtexparser@v2.0.0b6...v2.0.0b7)

---
updated-dependencies:
- dependency-name: bibtexparser
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -13,4 +13,4 @@ pytest-recording
 codecov
 vcrpy
 PyYAML
-bibtexparser == 2.0.0b6
+bibtexparser == 2.0.0b7