Update changelog.

.changelog-bugfix.md

@@ -6,4 +6,5 @@
 - Outdated GitHub Actions can now be printed via the build target `check_github_actions`. Alternatively, the build target `update_github_actions` may be used to update them automatically.
 - The build target `update_dependencies` can now be used to update Python dependencies. The build targets `update_build_dependencies` and `update_runtime_dependencies` only update build-time and runtime dependencies, respectively.
 - Continuous Integration is now used to automatically update outdated GitHub Actions on a regular schedule.
+- Continuous Integration is now used to automatically update outdated Python dependencies on a regular basis.
 - Continuous Integration is now used to periodically update the Doxygen configuration file used for generating API documentations for C++ code.