Don't run clang-tidy on test headers

This saves some time and doesn't lose anything - they only include
Boost headers and the test-class declaration.

.github/workflows/tidy.yml

@@ -14,7 +14,11 @@ jobs:
         sudo apt-get install -y clang-tidy-10 libboost-dev
     - name: Check
       run: |
-        find . -name *.[hc]pp -not -name config.*.hpp -not -name all.hpp -not -name quantlib.hpp -not -name paralleltestrunner.hpp | sort | xargs -n 1 ./tools/run_tidy.sh
+        find ql -name *.[hc]pp -not -name config.*.hpp -not -name all.hpp -not -name quantlib.hpp >> filelist
+        find test-suite -name *.cpp >> filelist
+        find Examples -name *.cpp >> filelist
+        cat filelist | sort | xargs -n 1 ./tools/run_tidy.sh
+        rm filelist
     - uses: peter-evans/create-pull-request@v3
       with:
         token: ${{ secrets.GITHUB_TOKEN }}