GHA: use julia-actions/cache some more

[fingolfin]

On https://github.com/Nemocas/Nemo.jl/actions/runs/7609008679?pr=1620 it complains:

[julia-buildpkg] Caching of the julia depot was not detected
Consider using julia-actions/cache to speed up runs https://github.com/julia-actions/cache. To ignore, set input ignore-no-cache: true

So this PR might resolve that -- and if it does, I assume something similar should be applied to our other repos?

[lgoettgens]

In oscar-system/Oscar.jl#3164, benlorenz added some few lines from https://github.com/julia-actions/cache#usage about permissions. This should be added here as well

[lgoettgens]

Error: Key Validation Error: julia-cache;workflow=OscarCI;job=test-oscar;os=Linux;branches-name=matching: [Oscar#master%2CHecke#master%2CSingular#master];branches-branch=mh/ci-cache;branches-pkgs-Oscar-options=[];branches-pkgs-Oscar-test=true;branches-pkgs-Oscar-branch=master;branches-pkgs-Hecke-options=["short"];branches-pkgs-Hecke-options-0=short;branches-pkgs-Hecke-test=true;branches-pkgs-Hecke-branch=master;branches-pkgs-Singular-options=[];branches-pkgs-Singular-test=true;branches-pkgs-Singular-branch=master;julia-version=~1.10.0-0;os=ubuntu-latest;run_id=8017144778;run_attempt=1 cannot be larger than 512 characters.

https://github.com/Nemocas/Nemo.jl/actions/runs/8017144778/job/21900453282?pr=1629#step:4:130

[benlorenz]

Error: Key Validation Error: julia-cache;workflow=OscarCI;job=test-oscar;os=Linux;branches-name=matching: [Oscar#master%2CHecke#master%2CSingular#master];branches-branch=mh/ci-cache;branches-pkgs-Oscar-options=[];branches-pkgs-Oscar-test=true;branches-pkgs-Oscar-branch=master;branches-pkgs-Hecke-options=["short"];branches-pkgs-Hecke-options-0=short;branches-pkgs-Hecke-test=true;branches-pkgs-Hecke-branch=master;branches-pkgs-Singular-options=[];branches-pkgs-Singular-test=true;branches-pkgs-Singular-branch=master;julia-version=~1.10.0-0;os=ubuntu-latest;run_id=8017144778;run_attempt=1 cannot be larger than 512 characters.

Nemocas/Nemo.jl/actions/runs/8017144778/job/21900453282?pr=1629#step:4:130

I guess this means that the automatic matrix key should be disabled and a custom key set, something like this in the oscar repo:

        with:
          cache-name: julia-cache;workflow=${{ github.workflow }};julia=${{ matrix.julia-version }};arch=${{ runner.arch }}
          include-matrix: false

[fingolfin]

ok I give up, if anyone is interested in this, please open a new pr