fix: remove check-changelog pre-commit hook (#39)

Now that the release process has been unified with other repos, this is
not needed. And as the hook command actually no longer exists, this
breaks contributions.

Author: tobice

.pre-commit-config.yaml

@@ -18,9 +18,3 @@ repos:
         entry: make unit-tests
         language: system
         pass_filenames: false
-
-      - id: check-changelog
-        name: Check whether current version is mentioned in changelog
-        entry: make check-changelog-entry
-        language: system
-        pass_filenames: false