Remove support for Python 3.8

Summary

Removed support for Python 3.8 and removed 3.8 tests from pipeline
https://gitlab.indiscale.com/caosdb/customers/f-fit/management/-/issues/106

Test Environment

Does the pipeline run successfully?

Check List for the Author

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• Annotations in code (Gitlab comments)

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

CHANGELOG.md

@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Removed ###
 
+* Support for Python 3.8
+
 ### Fixed ###
 
 * [#73](https://gitlab.com/linkahead/linkahead-pylib/-/issues/73)