refactor(pre-commit): use bundle exec for standardrb with single version source

Use BUNDLE_GEMFILE to run standardrb via bundle exec, ensuring the
pre-commit hook uses the version defined in the Gemfile. This makes
Renovate updates simpler - it only needs to update the Gemfile, and
the pre-commit hook automatically uses that version.

Benefits:
- Single source of truth for standard version (Gemfile only)
- Simpler Renovate updates (one file instead of two)
- Consistent version across all tools using the Gemfile

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: pedropombeiro

.pre-commit-config.yaml

@@ -64,12 +64,12 @@ repos:
     hooks:
       - id: standardrb
         name: standardrb (check)
-        entry: standardrb
+        entry: bash -c 'BUNDLE_GEMFILE=~/.shellrc/zshrc.d/functions/scripts/Gemfile bundle exec standardrb "$@"' --
         language: system
         types: [ruby]
       - id: standardrb-fix
         name: standardrb (fix)
-        entry: standardrb --fix
+        entry: bash -c 'BUNDLE_GEMFILE=~/.shellrc/zshrc.d/functions/scripts/Gemfile bundle exec standardrb --fix "$@"' --
         language: system
         types: [ruby]
         stages: [manual]