ci_find_tools misses changed tools if tool XML is unchanged

`ci_find_tools --changed_in_commit_range RANGE` seems not find changed tools if the main xml file is not changed (e.g. if only scripts or test-data is changed).

Not sure if this is the desired behavior, but the finding such tools would be needed in the IUC PR workflow in the linting step: https://github.com/galaxyproject/tools-iuc/blob/4daa375d022673d2437d609b1865b78c64b04415/.github/workflows/pr.yaml#L156

I guess for each non-xml file one would need to traverse the tree up to the repo root and take the first tool xml that is found in one of these paths.

Start with the `ci_find_tools --changed_in_commit_range RANGE` entry point and inspect its use in `.github/workflows/pr.yaml` at the linked linting step. Trace how changed paths are mapped to tools, then verify that changes to scripts or test data identify the nearest tool XML while unchanged XML still works.

Written by the indexing model from the issue text.