ci: Do not check commit messages with 'typos' due to false positives

Since commit c3777c1536 (ci: Extend spellcheck job with 'typos' tool,
2025-01-04) we check spelling with `typos` in addition to the
pre-existing check with `codespell`.  Unlike `codespell`, `typos` can
find typos in combined identifiers, e.g., `PascalCase` or `snake_case`.
That works well for code, but in commit messages it can trigger on
"words" in the middle of commit hashes.

.gitlab/ci/typos.bash

@@ -7,11 +7,8 @@ result=0
 echo "Running 'typos' on source code..."
 typos || result=1
 
-if [ -n "$CI_MERGE_REQUEST_DIFF_BASE_SHA" ]; then
-  for COMMIT in $(git rev-list "^$CI_MERGE_REQUEST_DIFF_BASE_SHA" "$CI_COMMIT_SHA"); do
-    echo "Running 'typos' on commit message of $COMMIT..."
-    git show --format=%B -s "$COMMIT" | typos - || result=1
-  done
-fi
+# FIXME(typos): checking commit messages hits false positives
+# on "words" inside commit hashes.  We'd need a way to disable
+# checking of combined identifiers to avoid this.
 
 exit $result