Remove DinD config from test projects used for DS, SAST QA

Problem to solve

Docker-in-Docker (DinD) for Dependency Scanning (DS) and DinD for SAST have been removed in #220540 (closed), but the test projects used for DS and SAST have not been updated, and many of them still use the master branch to test the DinD mode.

Implementation plan

1. Update the test projects used to tests SAST and DS:
   • Merge the no_dind-FREEZE branches into master
   • Rebase *-FREEZE branches
   • Rename no_dind-* branches, if any
   • Remove SAST_DISABLE_DIND and DS_DISABLE_DIND from CI configs
2. Update analyzer projects
   • Update shared CI config, and use master branch of test projects when doing DS QA gitlab-org/security-products/ci-templates!166 (merged)
   • Update CI config of SAST analyzer projects, and don't force branch of test projects to no_dind-FREEZE (10 MRs)
   • Update CI config of SAST analyzer projects to remove SAST_DISABLE_DIND (11 MRs)
3. Safely remove no_dind-FREEZE branches
   • Create no_dind-backup, in case we need to rebase branches that currently track no_dind-FREEZE
   • Delete no_dind-FREEZE branch in all test projects

These tasks are out of scope:

• rebase branches that currently track no_dind-FREEZE
• rename branches named after no_dind-FREEZE

Links / references