chore: remove pre-push from default install hook types

[puchy22]

Context

Pre-push hooks were running every push, slowing down the developer workflow even for routine pushes. The only check we still want enforced before pushing is secret detection (trufflehog); everything else (formatters, linters, security scanners) already runs at pre-commit time.

Description

• Drop pre-push from default_install_hook_types so prek install only registers pre-commit hooks by default.
• Keep trufflehog declared with stages: ["pre-commit", "pre-push"] so it remains available when developers opt in to the pre-push hook type (prek install --hook-type pre-push).
• Minor formatting cleanup: collapse a few multi-line args / files mappings onto single lines for readability.
• Update docs/developer-guide/introduction.mdx with a new Enable TruffleHog as a Pre-Push Hook subsection documenting the opt-in prek install --hook-type pre-push workflow.

No runtime behavior of Prowler changes — this only affects local developer tooling.

Steps to review

1. Inspect the diff in .pre-commit-config.yaml and docs/developer-guide/introduction.mdx.
2. Reinstall hooks locally:

   poetry run prek install

3. Confirm only pre-commit is installed:

   ls -la .git/hooks/ | grep -E 'pre-(commit|push)'

4. Optionally enable trufflehog on push (per the new docs section):

   poetry run prek install --hook-type pre-push

5. Verify a normal git push no longer triggers the previous pre-push hook chain, and that with the opt-in installed, TruffleHog runs on push.
6. Render docs/developer-guide/introduction.mdx and confirm the new subsection appears under Pre-Commit Hooks.

Checklist

Community Checklist

• This feature/issue is listed in here or roadmap.prowler.com
• Is it assigned to me, if not, request it via the issue/feature in here or Prowler Community Slack

• Review if the code is being covered by tests. (N/A — dev tooling config + docs only)
• Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings (N/A — no Python code changes)
• Review if backport is needed. (No)
• Review if is needed to change the Readme.md (No)
• Ensure new entries are added to CHANGELOG.md, if applicable. (N/A — internal dev tooling, no user-facing change)

SDK/CLI

• Are there new checks included in this PR? No

UI

• N/A

API

• N/A

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

✅ All necessary CHANGELOG.md files have been updated.

[github-actions]

✅ Conflict Markers Resolved

All conflict markers have been successfully resolved in this pull request.