Remove deprecated SAST jobs

What does this MR do and why?

Apply same changes as Remove deprecated SAST jobs (!178093 - merged) but to the stable CI templates.

I.e.:

• bandit-sast: removal overdue since 15.3
• brakeman-sast: removal overdue since 17.0
• eslint-sast: removal overdue since 15.3
• flawfinder-sast: removal overdue since 17.0
• gosec-sast: removal overdue since 15.2
• mobsf-android-sast: removal overdue since 17.0
• mobsf-ios-sast: removal overdue since 17.0
• nodejs-scan-sast: removal overdue since 17.0
• phpcs-security-audit-sast: removal overdue since 17.0
• security-code-scan-sast: removal overdue since 16.0

References

• SAST Deprecation: Analyzer consolidation and CI... (#352554 - closed)
• Static Analysis Analyzer consolidation in 16.0 (#390416 - closed)
• https://docs.gitlab.com/ee/update/deprecations.html#sast-analyzer-coverage-changing-in-gitlab-170

MR acceptance checklist

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Related to #390416 (closed)