[llvm] [ci] Add ids workflow for checking llvm apis have been annotated with LLVM_ABI (PR #128370)

[Andrew Rogers via llvm-commits]

andrurogerz wrote:

@mcbarton thanks for working on this! I took a quick look at the `idt` command in the job, and I see that you're not passing it the names of files to scan. In addition to passing it the comp database, I believe you also need to pass it the source files you specifically want it to scan as trailing arguments. 

Something like this would scan all the files in the top commit:
```
idt -p ${{ github.workspace }}/llvm-project/build --export-macro=LLVM_ABI $(git diff --name-only HEAD~1 HEAD)
```

https://github.com/llvm/llvm-project/pull/128370