Add name output to identify builder instance name

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

setup-buildx/__tests__/buildx.test.ts

@@ -8,7 +8,13 @@ const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'setup-buildx-'));
 describe('buildx', () => {
   it('is available', async () => {
     expect(await buildx.isAvailable()).toBe(true);
-  }, 100000);
+  });
+
+  it('count builders', async () => {
+    const countBuilders = await buildx.countBuilders();
+    console.log(`countBuilders: ${countBuilders}`);
+    expect(countBuilders).toBeGreaterThan(0);
+  });
 
   it('acquires v0.2.2 version of buildx', async () => {
     const buildxBin = await buildx.install('v0.2.2', tmpDir);