Remove unused files

• : remove master branch since we use main
• : there is many branches 1v*, are they used ? If not shall we delete them ?
• : Do the following files can be removed ? Most are either old or Python linter which are now handle by pre-commit or SQ
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/.pylintrc?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/.pylintrc3k?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/ci_example.py?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/runAutopep8.sh?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/runPylint.sh?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/tests/setup.cfg?ref_type=heads
  • https://gitlab.cta-observatory.org/cta-computing/dpps/CTADIRAC/-/blob/main/Singularity?ref_type=heads