Remove extra version info (#2539)

Follow up to https://github.com/dart-lang/test/pull/2538

This is only relevant when using the test runner as a git or path
dependency. In these cases the version will already end in `-WIP` with
our current development practices and in the places where it may come up
the users don't need help understanding where the code is coming from.

pkgs/test_core/lib/src/runner/version.dart

diff --git a/pkgs/test_core/lib/src/runner/version.dart b/pkgs/test_core/lib/src/runner/version.dart
index 05054ce..99f1e56 100644
--- a/pkgs/test_core/lib/src/runner/version.dart
+++ b/pkgs/test_core/lib/src/runner/version.dart
@@ -9,10 +9,8 @@
 import 'package:path/path.dart' as p;
 import 'package:yaml/yaml.dart';
 
-/// The version number of the test runner, or `null` if it couldn't be loaded.
-///
-/// This is a semantic version, optionally followed by a space and additional
-/// data about its source.
+/// The semantic version number of the test runner, or `null` if it couldn't be
+/// found.
 final String? testVersion = _readWorkspaceRef() ?? _readPubspecLock();
 
 String? _readWorkspaceRef() {
@@ -58,36 +56,8 @@
   if (packages is! Map) return null;
   var package = packages['test'];
   if (package is! Map) return null;
-
   var source = package['source'];
   if (source is! String) return null;
-
-  switch (source) {
-    case 'hosted':
-      var version = package['version'];
-      return (version is String) ? version : null;
-
-    case 'git':
-      var version = package['version'];
-      if (version is! String) return null;
-      var description = package['description'];
-      if (description is! Map) return null;
-      var ref = description['resolved-ref'];
-      if (ref is! String) return null;
-
-      return '$version (${ref.substring(0, 7)})';
-
-    case 'path':
-      var version = package['version'];
-      if (version is! String) return null;
-      var description = package['description'];
-      if (description is! Map) return null;
-      var path = description['path'];
-      if (path is! String) return null;
-
-      return '$version (from $path)';
-
-    default:
-      return null;
-  }
+  var version = package['version'];
+  return (version is String) ? version : null;
 }