Upgrade semgrep

Proposal

Upgrade semgrep to 0.50.1.

Why does this require an issue?

gitlab-org/security-products/analyzers/semgrep!32 (merged) sought to upgrade to 0.50.1, but the MR also shows that the latest version of semgrep combined with our rules doesn't find the same vulnerabilities in the downstream QA projects. The upgrade from 0.39.1 -> 0.50.1 brought changes to the way js/ts rules are interpreted. There is a chance that we need to modify our rules as well as a possibility of regression within semgrep itself.

Tasks

• Update semgrep to the latest (0.50.1 at the time of this issue's creation)
• Fix rules to still find vulnerabilities expected by downstream QA projects