[GitHub Actions] Enable CodeQL code scanning for our GitHub Actions/Workflows (Angular version)

[tdonohue]

References

• Backend version of this PR is at [GitHub Actions] Enable CodeQL code scanning for our GitHub Actions/Workflows DSpace#12813

Description

GitHub now supports security scanning of GitHub action/workflow files (under .github/workflows).

References:

• https://docs.github.com/en/code-security/reference/code-scanning/workflow-configuration-options#languages-to-be-analyzed

This small PR enables that security scanning for our Backend repository's GitHub actions,

NOTE: This PR also REMOVES the autobuild step because that step is only necessary for compiled languages like Java. In all recent runs of this codeql action, when the autobuild runs, it always reports None of the languages in this project require extra build steps

Instructions for Reviewers

• Review the configuration changes
• This can only be tested via code merger

[tdonohue]

Merging immediately as this has no changes to code. It just enables CodeQL security scanning for our GitHub Actions. (NOTE: I've realized that CodeQL settings only need to be on the main branch)