[CI] Temporarily disable tests requiring spirv-tools in CI

[uditagarwal97]

#16724 installed spirv-tools on Linux docker containers and now some llvm-spirv tests are failing due to this (example: https://github.com/intel/llvm/actions/runs/12915358763/job/36017038536).
In this PR, we disable detection of spirv-tools LIT feature temporarily in CI to fix post-commit.

[AlexeySachkov]

Approving to unblock fixing CI failures, but llvm-spirv changes should either be upstreamed, or tracked in #7592 to remind us to revert them

[maarquitos14]

I'm okay with merging this to fix post-commit.

About the root cause, the problem seems to be that the path for all spirv-tools binaries is not found:

llvm-lit: /__w/llvm/llvm/src/llvm/utils/lit/lit/llvm/subst.py:126: note: Did not find spirv-as in SPIRV_AS_PATH-NOTFOUND
llvm-lit: /__w/llvm/llvm/src/llvm/utils/lit/lit/llvm/subst.py:126: note: Did not find spirv-dis in SPIRV_AS_PATH-NOTFOUND
llvm-lit: /__w/llvm/llvm/src/llvm/utils/lit/lit/llvm/subst.py:[12](https://github.com/intel/llvm/actions/runs/12918158681/job/36026109985#step:14:13)6: note: Did not find spirv-link in SPIRV_AS_PATH-NOTFOUND
llvm-lit: /__w/llvm/llvm/src/llvm/utils/lit/lit/llvm/subst.py:126: note: Did not find spirv-val in SPIRV_AS_PATH-NOTFOUND

I'm not sure why, I cannot reproduce locally. If you help me reproduce the issue, I can try and fix it.

[uditagarwal97]

@intel/llvm-gatekeepers I think we are good to merge this.