Try to make code logic more clear

Author: mhucka

.github/workflows/_find_changes.yaml

@@ -33,10 +33,10 @@ on:
   workflow_call:
     outputs:
       code:
-        description: 'True if any code files were changed'
-        value: ${{jobs.test.outputs.only-noncode-changes == 'false'}}
+        description: 'True if any potential code file was changed'
+        value: ${{jobs.test.outputs.nondoc-file-changes == 'true'}}
       python:
-        description: 'True if Python files were changed'
+        description: 'True if any Python file was changed'
         value: ${{jobs.test.outputs.python-changes == 'true'}}
 
 permissions: read-all
@@ -47,24 +47,34 @@ jobs:
     runs-on: ubuntu-24.04
     timeout-minutes: 5
     outputs:
-      only-noncode-changes: ${{steps.only-noncode-files.outputs.matched}}
+      nondoc-file-changes: ${{steps.nondoc-files.outputs.matched}}
       python-changes: ${{steps.python-files.outputs.matched}}
     steps:
       - name: Check out a copy of the git repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
 
-      - name: Test whether only docs or similar files were changed
+      - name: Test whether the changes involved one or more non-doc files
         uses: tomi/paths-filter-action@32c62f5ca100c1110406e3477d5b3ecef4666fec # v3.0.2
-        id: only-noncode-files
+        id: nondoc-files
         with:
           base: ${{github.ref_name}}
-          predicate-quantifier: 'every'
+          # Note: when editing the patterns below, always make sure to negate
+          # the condition (i.e., use a leading '!'). See the next comment.
           filters: |
             matched:
-              - '!**/*.md'
-              - '!docs/**'
               - '!.github/ISSUE_TEMPLATE/**'
+              - '!.github/dependabot.yaml'
+              - '!.github/problem-matchers/**'
               - '!CITATION.cff'
+              - '!docs/**'
+              - '!**/*.md'
+              - '!**/*.png'
+          # The default paths-filter-action behavior is "match at least one"
+          # pattern. We change the behavior to be "match every" pattern.
+          # Combined with negating every pattern above, it means the final output
+          # will be non-empty only if there is at least one file that is NOT a
+          # documentation file, or in other words, is a potential code file.
+          predicate-quantifier: 'every'
 
       - name: Test whether Python files are among the changed files
         uses: tomi/paths-filter-action@32c62f5ca100c1110406e3477d5b3ecef4666fec # v3.0.2
@@ -78,5 +88,5 @@ jobs:
       - name: Summary of test results
         run: |
           set -x
-          echo steps.only-noncode-files.outputs.matched = │${{steps.only-noncode-files.outputs.matched}}│
+          echo steps.nondoc-files.outputs.matched = │${{steps.nondoc-files.outputs.matched}}│
           echo steps.python-files.outputs.matched = │${{steps.python-files.outputs.matched}}│