[Build] Setup Dependabot and CodeQL for SecOps

[xames3]

• this issue is more or less housekeeping involved and can be worked alongside the setting up actions workflow issue. the obvious deliverables for successful closure of this issue would be:

  • [ ] setting up a dependabot workflow for keeping the repository and requirements up-to-date with proper security vulnerabilities check.

ideally, it should be taken up alongside the workflows issue.

[xames3]

• codeQL has been enabled. although the repository doesn't consist any relevant code to scan through, I've still added the codeQL as a safeguarding option.
• have also enabled checking for any secrets on push. this can certainly avoid spoilers.