Remove the test: all feature. (#4722)

Closes flutter/flutter#169374.

Author: matanlurey

app_dart/lib/src/service/scheduler.dart

@@ -892,26 +892,6 @@ $s
             )
             .toList();
 
-    // See https://github.com/flutter/flutter/issues/138430.
-    final includePostsubmitAsPresubmit = _includePostsubmitAsPresubmit(
-      inner,
-      pullRequest,
-    );
-    if (includePostsubmitAsPresubmit) {
-      log.info(
-        'Including postsubmit targets as presubmit for ${pullRequest.number}',
-      );
-
-      for (var target in inner.postsubmitTargets) {
-        // We don't want to include a presubmit twice
-        // We don't want to run the builder_cache target as a presubmit
-        if (!target.presubmit &&
-            !target.getProperties().containsKey('cache_name')) {
-          presubmitTargets.add(target);
-        }
-      }
-    }
-
     log.info('Collected ${presubmitTargets.length} presubmit targets.');
     // Release branches should run every test.
     if (pullRequest.base!.ref !=
@@ -921,12 +901,6 @@ $s
       );
       return presubmitTargets;
     }
-    if (includePostsubmitAsPresubmit) {
-      log.info(
-        'Postsubmit targets included as presubmit, scheduling all targets for ${pullRequest.number}',
-      );
-      return presubmitTargets;
-    }
 
     // Filter builders based on the PR diff
     final filesChanged = await _getFilesChanged.get(
@@ -936,23 +910,6 @@ $s
     return getTargetsToRun(presubmitTargets, filesChanged);
   }
 
-  static final _allowTestAll = {Config.flutterSlug};
-
-  /// Returns `true` if [ciYaml.postsubmitTargets] should be ran during presubmit.
-  static bool _includePostsubmitAsPresubmit(
-    CiYaml ciYaml,
-    PullRequest pullRequest,
-  ) {
-    if (!_allowTestAll.contains(ciYaml.slug)) {
-      return false;
-    }
-    if (pullRequest.labels?.any((label) => label.name.contains('test: all')) ??
-        false) {
-      return true;
-    }
-    return false;
-  }
-
   /// Process a completed GitHub `check_run`.
   ///
   /// Handles both fusion engine build and test stages, and both pull requests

app_dart/test/service/scheduler_test.dart

@@ -2139,99 +2139,6 @@ targets:
         );
       });
 
-      group('treats postsubmit as presubmit if a label is present', () {
-        final runAllTests = IssueLabel(name: 'test: all');
-        setUp(() async {
-          ciYamlFetcher.setCiYamlFrom(r'''
-enabled_branches:
-    - main
-    - master
-targets:
-  - name: Linux Presubmit
-    presubmit: true
-    scheduler: luci
-  - name: Linux Conditional Presubmit (runIf)
-    presubmit: true
-    scheduler: luci
-    runIf:
-      - .ci.yaml
-      - DEPS
-      - dev/run_if/**
-  - name: Linux Postsubmit
-    presubmit: false
-    scheduler: luci
-  - name: Linux Cache
-    presubmit: false
-    scheduler: luci
-    properties:
-      cache_name: "builder"
-          ''');
-        });
-
-        test('with a specific label in the flutter/engine repo', () async {
-          final enginePr = generatePullRequest(
-            branch: Config.defaultBranch(Config.flutterSlug),
-            labels: <IssueLabel>[runAllTests],
-            repo: Config.flutterSlug.name,
-          );
-          final presubmitTargets = await scheduler.getPresubmitTargets(
-            enginePr,
-          );
-          expect(presubmitTargets.map((Target target) => target.name).toList(), <
-            String
-          >[
-            // Always runs.
-            'Linux Presubmit',
-            // test: all label is present, so runIf is skipped.
-            'Linux Conditional Presubmit (runIf)',
-            // test: all label is present, so postsubmit is treated as presubmit.
-            'Linux Postsubmit',
-          ]);
-        });
-
-        test('with a specific label in the flutter/flutter repo', () async {
-          final frameworkPr = generatePullRequest(
-            branch: Config.defaultBranch(Config.flutterSlug),
-            labels: <IssueLabel>[runAllTests],
-            repo: Config.flutterSlug.name,
-          );
-          final presubmitTargets = await scheduler.getPresubmitTargets(
-            frameworkPr,
-          );
-          expect(presubmitTargets.map((Target target) => target.name).toList(), <
-            String
-          >[
-            // Always runs.
-            'Linux Presubmit',
-            // test: all label is present, so runIf is skipped.
-            'Linux Conditional Presubmit (runIf)',
-            // test: all label is present, so postsubmit is treated as presubmit.
-            'Linux Postsubmit',
-          ]);
-        });
-
-        test('without a specific label', () async {
-          final enginePr = generatePullRequest(
-            branch: Config.defaultBranch(Config.flutterSlug),
-            labels: <IssueLabel>[],
-            repo: Config.flutterSlug.name,
-          );
-
-          // Assume a file that is not runIf'd was changed.
-          getFilesChanged.cannedFiles = ['README.md'];
-          final presubmitTargets = await scheduler.getPresubmitTargets(
-            enginePr,
-          );
-          expect(
-            presubmitTargets.map((Target target) => target.name).toList(),
-            <String>[
-              // Always runs.
-              'Linux Presubmit',
-            ],
-          );
-        });
-      });
-
       test('checks for release branches', () async {
         const branch = 'flutter-1.24-candidate.1';
         ciYamlFetcher.setCiYamlFrom(r'''