fix(@angular-devkit/build-angular): use absolute watch paths for postcss dependency messages

Postcss's directory dependency message can use a glob pattern to reflect that multiple files
within a given directory should be watched. When calculated the complete file set, the paths
must be absolute to ensure that the watch system correctly invalidates the stylesheet being
processed.

(cherry picked from commit 376e346)

Author: clydin

packages/angular_devkit/build_angular/src/tools/esbuild/stylesheets/stylesheet-plugin-factory.ts

@@ -283,7 +283,10 @@ async function compileString(
         typeof resultMessage['glob'] === 'string'
       ) {
         loadResult.watchFiles ??= [];
-        const dependencies = await glob(resultMessage['glob'], { cwd: resultMessage['dir'] });
+        const dependencies = await glob(resultMessage['glob'], {
+          absolute: true,
+          cwd: resultMessage['dir'],
+        });
         loadResult.watchFiles.push(...dependencies);
       }
     }