fix: Update coverage omit files

Files that don't end with .py or .pyo ot .pyc are automatically
skipped by coveragepy. Updated omit list accordingly to remove non
python importable files.

ref: https://coverage.readthedocs.io/en/coverage-5.5/source.html#execution

.github/workflows/server-mariadb-tests.yml

@@ -91,7 +91,6 @@ jobs:
           DB: mariadb
           TYPE: server
 
-
       - name: Run Tests
         run: cd ~/frappe-bench/ && bench --site test_site run-parallel-tests --use-orchestrator --with-coverage
         env:

frappe/commands/utils.py

@@ -573,18 +573,15 @@ def run_tests(context, app=None, module=None, doctype=None, test=(), profile=Fal
 		# Generate coverage report only for app that is being tested
 		source_path = os.path.join(get_bench_path(), 'apps', app or 'frappe')
 		omit=[
-			'*.html',
-			'*.js',
-			'*.xml',
-			'*.css',
-			'*.less',
-			'*.scss',
-			'*.vue',
+			'*.pyc',
+			'*/test_*',
+			'*/node_modules/*',
 			'*/doctype/*/*_dashboard.py',
 			'*/patches/*'
 		]
 
 		if not app or app == 'frappe':
+			omit.append('*/tests/*')
 			omit.append('*/commands/*')
 
 		cov = Coverage(source=[source_path], omit=omit)