chore(deps): Pin dependencies

pin actions/checkout action to 11bd719
pin savonet/github-actions-cpu-cores-docker action to f72bcfa
pin actions/setup-node action to 39370e3
pin crazy-max/ghaction-github-pages action to fbf0a4f
pin actions/upload-artifact action to 6f51ac0
pin peaceiris/actions-gh-pages action to 4f9cc66
pin ocaml/setup-ocaml action to 778844f
pin actions/cache action to 1bd1e32
pin pre-commit/action action to 2c7b380
pin actions/download-artifact action to fa0a91b
pin softprops/action-gh-release action to c95fe14
pin docker/setup-buildx-action action to 6524bf6
pin docker/login-action action to 9780b0c
pin docker/build-push-action action to b32b51a
pin savonet/liquidsoap-ci docker tag to a9e3ce5
pin ubuntu github-runner to v24.04