[pre-commit] add 'tomli' dependency for codespell pre-commit hook

The codespell pre-commit hook imports the 'tomllib' module to parse
'pyproject.toml'.  'tomllib' is not available for Python versions 3.10
and older.  Add a dependency on 'tomli' so the hook also works on these
Python versions.

Approved-By: Tom de Vries <tdevries@suse.de>

.pre-commit-config.yaml

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 66cbc11..8ff84da 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -86,10 +86,13 @@
       - id: codespell
         args: &codespell_args [--toml, gdb/pyproject.toml]
         files: &gdb_files '^(gdb|gdbserver|gdbsupport)/'
+        # 'tomllib' library is not available on Python < 3.11.
+        additional_dependencies: &codespell_deps ['tomli']
       - id: codespell
         name: codespell-log
         entry: gdb/contrib/codespell-log.sh
         args: *codespell_args
+        additional_dependencies: *codespell_deps
         verbose: true
         stages: [commit-msg]