Fix 302 on /favicon.ico (#137294) (#137461)

(cherry picked from commit a40d241388)

Co-authored-by: Gerard Soldevila <gerard.soldevila@elastic.co>
Co-authored-by: Spencer <spencer@elastic.co>

src/dev/build/tasks/copy_source_task.ts

@@ -23,6 +23,7 @@ export const CopySource: Task = {
         '!src/**/*.{test,test.mocks,mock}.{js,ts,tsx}',
         '!src/**/mocks.ts', // special file who imports .mock files
         '!src/**/{target,tests,__jest__,test_data,__tests__,__snapshots__,__mocks__,integration_tests,__fixtures__}/**',
+        '!src/core/server/core_app/assets/favicons/favicon.distribution.ico',
         '!src/core/server/core_app/assets/favicons/favicon.distribution.png',
         '!src/core/server/core_app/assets/favicons/favicon.distribution.svg',
         '!src/test_utils/**',

src/dev/build/tasks/replace_favicon.ts

@@ -12,6 +12,11 @@ export const ReplaceFavicon: Task = {
   description: 'Replacing favicons with built version',
 
   async run(config, log, build) {
+    await copy(
+      config.resolveFromRepo('src/core/server/core_app/assets/favicons/favicon.distribution.ico'),
+      build.resolvePath('src/core/server/core_app/assets/favicons/favicon.ico')
+    );
+
     await copy(
       config.resolveFromRepo('src/core/server/core_app/assets/favicons/favicon.distribution.png'),
       build.resolvePath('src/core/server/core_app/assets/favicons/favicon.png')