[llvm] [Github] Build BOLT docs on changes (PR #226747)

[Amilendra Kodithuwakku via llvm-commits]

amilendra wrote:

@boomanaiden154 

I think `utils/docs/*` also needs to be added to the bolt docs build conditions in the workflow.


The present conditions are
```
          steps.docs-changed-subprojects.outputs.bolt_any_changed == 'true' ||
          steps.docs-changed-subprojects.outputs.workflow_any_changed == 'true'
```

The changes to `utils/docs/*` in #223829 required changes to the bolt docs, but the #223829 commit checks did not catch that because the present conditions caused bolt docs builds to be [skipped](https://github.com/llvm/llvm-project/actions/runs/36038459772/job/107764338273).
If `utils/docs/*` were in the conditions the bolt docs build break would have been caught early.

https://github.com/llvm/llvm-project/pull/226747