Only check project src directory on precommit

[johnatawnclementawn]

Types of changes

• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Description of Change

Reduces drift in configuration of precommit and package.json scripts

Issues Solved

Closes #

Checklist

• I targeted one of these branches:
  • [x] dev/7.6.x (under development): features, bugfixes not covered below
  • [ ] dev/7.5.x (main support): regressions, crashing bugs, security issues, major bugs in new features
  • [ ] dev/6.2.x (extended support): major security issues, data loss issues
• [ ] I added a changelog in arches/releases
• [ ] I submitted a PR to arches-docs (if appropriate)
• [ ] Unit tests pass locally with my changes
• [ ] I added tests that prove my fix is effective or that my feature works
• [ ] My test fails on the target branch

Accessibility Checklist

Developer Guide

Topic	Changed	Retested
Color contrast
Form fields
Headings
Links
Keyboard
Responsive Design
HTML validation
Screen reader

Ticket Background

• Sponsored by:
• Found by: @
• Tested by: @
• Designed by: @

Further comments

[jacobtylerwalls]

We were finding that without this change, a manage.py updateproject (after the latest webpack changes that just landed) created unstaged files under /webpack that were linted by pre-commit in unintended ways (e.g. messages about forbidding require that only make sense for typescript).

We could consider linting these files in the future, but since we're not linting them in core, suggest not to lint them in projects. The invocation through npm run ... was already excluding them, so as Johnathan mentions, the idea here is to just remove the drift.