Fix the problem that bundle files are not changed in development mode (#6073)

#### What type of PR is this?

/kind regression
/area plugin
/milestone 2.17.x

#### What this PR does / why we need it:

This PR reverts changes of generating bundle resource version in <https://github.com/halo-dev/halo/pull/6028>.

Because the changes were adapted realtime change of bundle files for plugin developers in plugin development runtime mode, but I ignored it.

#### Special notes for your reviewer:

1. Try to start Halo in plugin development mode
2. Change and rebuild ui resources
3. Refresh console and check the result

#### Does this PR introduce a user-facing change?

```release-note
None
```

application/src/main/java/run/halo/app/core/extension/service/impl/PluginServiceImpl.java

@@ -14,6 +14,7 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.time.Clock;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -90,6 +91,8 @@ public class PluginServiceImpl implements PluginService, InitializingBean, Dispo
 
     private final Scheduler scheduler = Schedulers.boundedElastic();
 
+    private Clock clock = Clock.systemUTC();
+
     public PluginServiceImpl(ReactiveExtensionClient client, SystemVersionSupplier systemVersion,
         PluginProperties pluginProperties, SpringPluginManager pluginManager) {
         this.client = client;
@@ -101,6 +104,16 @@ public class PluginServiceImpl implements PluginService, InitializingBean, Dispo
         this.cssBundleCache = new BundleCache(".css");
     }
 
+    /**
+     * The method is only for testing.
+     *
+     * @param clock new clock
+     */
+    void setClock(Clock clock) {
+        Assert.notNull(clock, "Clock must not be null");
+        this.clock = clock;
+    }
+
     @Override
     public Flux<Plugin> getPresets() {
         // list presets from classpath
@@ -269,6 +282,9 @@ public class PluginServiceImpl implements PluginService, InitializingBean, Dispo
 
     @Override
     public Mono<String> generateBundleVersion() {
+        if (pluginManager.isDevelopment()) {
+            return Mono.just(String.valueOf(clock.instant().toEpochMilli()));
+        }
         return Flux.fromIterable(new ArrayList<>(pluginManager.getStartedPlugins()))
             .sort(Comparator.comparing(PluginWrapper::getPluginId))
             .map(pw -> pw.getPluginId() + ':' + pw.getDescriptor().getVersion())

application/src/test/java/run/halo/app/core/extension/service/impl/PluginServiceImplTest.java

@@ -23,6 +23,9 @@ import java.net.URISyntaxException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
@@ -249,7 +252,6 @@ class PluginServiceImplTest {
 
     }
 
-
     @Test
     void generateBundleVersionTest() {
         var plugin1 = mock(PluginWrapper.class);
@@ -297,6 +299,19 @@ class PluginServiceImplTest {
         assertThat(result).isNotEqualTo(result2);
     }
 
+    @Test
+    void shouldGenerateRandomBundleVersionInDevelopment() {
+        var clock = Clock.fixed(Instant.now(), ZoneId.systemDefault());
+        pluginService.setClock(clock);
+        when(pluginManager.isDevelopment()).thenReturn(true);
+        pluginService.generateBundleVersion()
+            .as(StepVerifier::create)
+            .expectNext(String.valueOf(clock.instant().toEpochMilli()))
+            .verifyComplete();
+
+        verify(pluginManager, never()).getStartedPlugins();
+    }
+
     @Nested
     class PluginStateChangeTest {