Reorganize workflow to validate syntax after tests (#211)

Reordered steps to validate source syntax after testing mods.

.github/workflows/validate-mods.yml

@@ -24,9 +24,6 @@ jobs:
 
       - uses: actions/checkout@v4
 
-      - name: Validate source syntax
-        run: bash src/Scripts/test/test-syntax.sh all
-
       - name: Download deb artifact
         uses: actions/download-artifact@v4
         with:
@@ -42,3 +39,6 @@ jobs:
 
       - name: Test all mods
         run: bash src/Scripts/test/test-patches.sh all
+
+      - name: Validate source syntax
+        run: bash src/Scripts/test/test-syntax.sh all