fix(@angular-devkit/build-angular): remove double-watch in karma

The Karma file watching was racing with the file writes done by the
application builder. Since we already tell Karma when to reun via
`.refeshFiles()`, disabling Karma's own file watcher should make
things more reliable.

This allows removing a weird special-case in the test case and
removes the noisy "File chaned" logs generated by Karma.

Fixes #28755

Author: hybrist

packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts

@@ -265,28 +265,33 @@ async function initializeApplication(
   karmaOptions.files ??= [];
   karmaOptions.files.push(
     // Serve polyfills first.
-    { pattern: `${outputPath}/polyfills.js`, type: 'module' },
+    { pattern: `${outputPath}/polyfills.js`, type: 'module', watched: false },
     // Serve global setup script.
-    { pattern: `${outputPath}/${mainName}.js`, type: 'module' },
+    { pattern: `${outputPath}/${mainName}.js`, type: 'module', watched: false },
     // Serve all source maps.
-    { pattern: `${outputPath}/*.map`, included: false },
+    { pattern: `${outputPath}/*.map`, included: false, watched: false },
   );
 
   if (hasChunkOrWorkerFiles(buildOutput.files)) {
     karmaOptions.files.push(
       // Allow loading of chunk-* files but don't include them all on load.
-      { pattern: `${outputPath}/{chunk,worker}-*.js`, type: 'module', included: false },
+      {
+        pattern: `${outputPath}/{chunk,worker}-*.js`,
+        type: 'module',
+        included: false,
+        watched: false,
+      },
     );
   }
 
   karmaOptions.files.push(
     // Serve remaining JS on page load, these are the test entrypoints.
-    { pattern: `${outputPath}/*.js`, type: 'module' },
+    { pattern: `${outputPath}/*.js`, type: 'module', watched: false },
   );
 
   if (options.styles?.length) {
     // Serve CSS outputs on page load, these are the global styles.
-    karmaOptions.files.push({ pattern: `${outputPath}/*.css`, type: 'css' });
+    karmaOptions.files.push({ pattern: `${outputPath}/*.css`, type: 'css', watched: false });
   }
 
   const parsedKarmaConfig: Config & ConfigOptions = await karma.config.parseConfig(

packages/angular_devkit/build_angular/src/builders/karma/tests/behavior/rebuilds_spec.ts

@@ -11,7 +11,7 @@ import { execute } from '../../index';
 import { BASE_OPTIONS, KARMA_BUILDER_INFO, describeKarmaBuilder } from '../setup';
 import { BuilderOutput } from '@angular-devkit/architect';
 
-describeKarmaBuilder(execute, KARMA_BUILDER_INFO, (harness, setupTarget, isApplicationBuilder) => {
+describeKarmaBuilder(execute, KARMA_BUILDER_INFO, (harness, setupTarget) => {
   describe('Behavior: "Rebuilds"', () => {
     beforeEach(async () => {
       await setupTarget(harness);
@@ -45,13 +45,6 @@ describeKarmaBuilder(execute, KARMA_BUILDER_INFO, (harness, setupTarget, isAppli
           expect(result?.success).toBeTrue();
         },
       ];
-      if (isApplicationBuilder) {
-        expectedSequence.unshift(async (result) => {
-          // This is the initial Karma run, it should succeed.
-          // For simplicity, we trigger a run the first time we build in watch mode.
-          expect(result?.success).toBeTrue();
-        });
-      }
 
       const buildCount = await harness
         .execute({ outputLogsOnFailure: false })