ci(tool): Improve concurrent CI
- Add ccache for LLVM builds
- Run check-mlir in parallel by adding
-j $(nproc). - Change GIT_STRATEGY to the default to fix some sporadic failures
- Merge build and test steps (temporarily) to fix artifact-passing issue
Signed-off-by: Ian Tayler Lessa ian.taylerlessa@arm.com Signed-off-by: Iliyan Georgiev iliyan.georgiev@arm.com
Edited by Ian Tayler Lessa