Fix code coverage collection for integration tests. (#8324)

Author: isoos

pkg/code_coverage/lib/test_runner.dart

@@ -98,7 +98,6 @@ Future<Process> _startCollect(int port, String outputFile) async {
   final p = await Process.start(
     'dart',
     [
-      'pub',
       'run',
       'coverage:collect_coverage',
       '--uri=http://localhost:$port',
@@ -123,7 +122,6 @@ Future<void> _convertToLcov(
   await Process.run(
     'dart',
     [
-      'pub',
       'run',
       'coverage:format_coverage',
       '--packages',

pkg/pub_integration/lib/src/fake_pub_server_process.dart

@@ -261,7 +261,6 @@ class _CoverageConfig {
     _process = await Process.start(
       'dart',
       [
-        'pub',
         'run',
         'coverage:collect_coverage',
         '--uri=http://localhost:$vmPort',