Bump pip from 21.3.1 to 23.3

Bumps [pip](https://github.com/pypa/pip) from 21.3.1 to 23.3.
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@21.3.1...23.3)

---
updated-dependencies:
- dependency-name: pip
  dependency-type: direct:production
...

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

requirements.txt

@@ -3,6 +3,6 @@ biopython==1.79
 coverage==6.2
 codecov==2.1.11
 pytest==6.2.5
-pip==21.3.1
+pip==23.3
 click==8.0.3
 pdb-tools==2.4.1