ci(pr): exclude skills/**/evals/** from test-trigger filters (#1170)

## Summary

The `changed-files` filter groups in `.github/workflows/pr.yaml`
(`test_cpp`, `test_python_conda`, `test_python_wheels`) already exclude
`skills/**/SKILL.md` and `skills/**/resources/**` so doc-only changes to
those paths skip the build/test pipeline. The same exclusion was missing
for `skills/**/evals/**`, so adding or editing an `evals.json`
unnecessarily triggers `conda-cpp-build`, `conda-python-build`, the
wheel builds, and downstream tests.

This PR adds `'!skills/**/evals/**'` to the three test-trigger filter
groups, matching the treatment of other non-buildable skill content.

## Notes

- `build_docs` is intentionally **not** changed — it does not exclude
`SKILL.md` or `resources/**` either, so docs-build behavior is unchanged
for all skill content.
- Verified by:
- `python3 -c "import yaml;
yaml.safe_load(open('.github/workflows/pr.yaml'))"` — YAML parses
  - `pre-commit run --files .github/workflows/pr.yaml` — all hooks pass

Signed-off-by: Ramakrishna Prabhu <[email protected]>

Author: rgsl888prabhu

.github/workflows/pr.yaml

@@ -223,6 +223,7 @@ jobs:
           - '!notebooks/**'
           - '!python/**'
           - '!skills/**/SKILL.md'
+          - '!skills/**/evals/**'
           - '!skills/**/resources/**'
           - '!sonar-project.properties'
           - '!sonarqube/**'
@@ -282,6 +283,7 @@ jobs:
           - '!ngc/**'
           - '!notebooks/**'
           - '!skills/**/SKILL.md'
+          - '!skills/**/evals/**'
           - '!skills/**/resources/**'
           - '!sonar-project.properties'
           - '!sonarqube/**'
@@ -342,6 +344,7 @@ jobs:
           - '!ngc/**'
           - '!notebooks/**'
           - '!skills/**/SKILL.md'
+          - '!skills/**/evals/**'
           - '!skills/**/resources/**'
           - '!sonar-project.properties'
           - '!sonarqube/**'