Make uploads resources protected (#7456)

#### What type of PR is this?

/kind improvement
/area core
/milestone 2.21.x

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

This PR removes `/uploads/**` from static resources to make it protected by Halo security.

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

```release-note
None
```

application/src/main/java/run/halo/app/infra/config/WebServerSecurityConfig.java

@@ -64,7 +64,6 @@ public class WebServerSecurityConfig {
             "/uc/assets/**",
             "/themes/{themeName}/assets/{*resourcePaths}",
             "/plugins/{pluginName}/assets/**",
-            "/upload/**",
             "/webjars/**",
             "/js/**",
             "/styles/**",