Fix CI

[PhilippvK]

• Fixed failing download in lint job
• Increase runner disk space to avoid running out of storage
• Update actions to latest versions

One CI job (unit (elem, cv32e40x)) is still failing but AFAIK this was already an issue a year ago:

[23702] %Error: vproc_core_sva.svh:22: Assertion failed in TOP.vproc_top.v_core: attempt to commit instruction ID 3, which already had a commit transaction
%Error: /home/runner/work/vicuna/vicuna/sim//../sva//vproc_core_sva.svh:22: Verilog $stop