fix(@angular/build): show full aggregate errors from vitest

Vitest may throw an `AggregateError` which can contain one or more specific
errors. The output console logging will now show each of these specific
errors in addition to the main thrown error.

(cherry picked from commit d556c60)

Author: clydin

packages/angular/build/src/builders/unit-test/builder.ts

@@ -146,6 +146,13 @@ async function* runBuildAndTest(
     } catch (e) {
       assertIsError(e);
       context.logger.error(`An exception occurred during test execution:\n${e.stack ?? e.message}`);
+      if (e instanceof AggregateError) {
+        e.errors.forEach((inner) => {
+          assertIsError(inner);
+          context.logger.error(inner.stack ?? inner.message);
+        });
+      }
+
       yield { success: false };
       consecutiveErrorCount++;
     }