update to 28.4.0 (#648)

Bump the v28 docs to the 28.4.0 release:

- point the `28` version variables (`version`, `sourceVersion`, `dockerVersion`, `displayVersion`) at 28.4.0
- update the v28 entry in `update_api_docs.sh` to `28.4.0`
- regenerate `static/swagger-28.json` and `static/openapi3-28.json` from the `v28.4.0` tag, which marks `path` as required in `CreatePullReviewComment` (go-gitea/gitea#40260)

Reviewed-on: https://gitea.com/gitea/docs/pulls/648
Reviewed-by: TheFox0x7 <[email protected]>

packages/content-loader/src/products.ts

@@ -89,11 +89,11 @@ const variables: Record<string, VersionVariables> = {
     goVersion: '1.27',
     minGoVersion: '1.27',
     minNodeVersion: '22',
-    version: '28.3.0',
-    sourceVersion: 'v28.3.0',
+    version: '28.4.0',
+    sourceVersion: 'v28.4.0',
     sourceBranch: 'release/v28',
-    dockerVersion: '28.3.0',
-    displayVersion: '28.3.0',
+    dockerVersion: '28.4.0',
+    displayVersion: '28.4.0',
   },
   '1.27': {
     goVersion: '1.26',