fix: scope coverage to src/backend and exclude tests folder

- Changed --cov=. to --cov=src/backend to measure only backend source code
- Added --omit=*/tests/* to exclude test files from coverage measurement
- Removed demo from target branches
- Fixed duplicate main entry in PR branches

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Rafi-Microsoft

.github/workflows/test.yml

@@ -5,7 +5,6 @@ on:
     branches:
       - main
       - dev
-      - demo
       - hotfix
   pull_request:
     types:
@@ -14,10 +13,8 @@ on:
       - reopened
       - synchronize
     branches:
-      - main
       - main
       - dev
-      - demo
       - hotfix
 
 permissions:
@@ -53,11 +50,12 @@ jobs:
             echo "Test files found, running tests."
             echo "skip_tests=false" >> $GITHUB_ENV
           fi
+
       - name: Run tests with coverage
         if: env.skip_tests == 'false'
         run: |
-          pytest --cov=. --cov-report=term-missing --cov-report=xml --junitxml=pytest.xml --ignore=tests/e2e-test/tests
-          
+          pytest --cov=src/backend --cov-report=term-missing --cov-report=xml --junitxml=pytest.xml --ignore=tests/e2e-test/tests --omit="*/tests/*"
+
       - name: Pytest Coverage Comment
         if: |
           always() &&