pre-commit: Remove outdated comment

We no longer use commit hash but a version. Because the same comment
has been removed from other repos, we can remove it in this repo as
well.

Also remove the redundant default_language_version option.

In addition, bump pre-commit to 4.5.0 which is now more commonly used.

Change-Id: I8556d117a076814c999070d755adc8a8a745b6e1

.pre-commit-config.yaml

@@ -1,15 +1,6 @@
-# We from the Oslo project decided to pin repos based on the
-# commit hash instead of the version tag to prevend arbitrary
-# code from running in developer's machines.  To update to a
-# newer version, run `pre-commit autoupdate` and then replace
-# the newer versions with their commit hash.
-
-default_language_version:
-  python: python3
-
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v4.5.0
     hooks:
       - id: trailing-whitespace
       # Replaces or checks mixed line ending