[llvm] [bazel] update .bazelversion to 8.0.0 (PR #119425)

[Nick Desaulniers via llvm-commits]

nickdesaulniers wrote:

> warning: input 'external/llvm-project/llvm/utils/lit/tests/shtest-run-at-line.py' contained no tests
> error: did not discover any tests for provided path(s)

I think is the relevant error?

https://github.com/llvm/llvm-project/pull/119425