Document runner 4 and 5, regenerate the 28.2.0 api documents (#599)

The 28.2.0 bump in #594 only changed the version string of the api documents, so they still listed the 28.1.0 endpoints. They are now regenerated from v28.2.0 (mostly new `423 repoArchivedError` responses).

The runner docs stopped at 3.3.0 while the runner is at 5.1.1:

- cut the runner `4` and `5` series, `/runner/` now serves 5.1.1 and `/runner/4/` 4.1.0, the `3` series is bumped to 3.5.0
- series specific image tags and versions in the new copies, the `3` series no longer claims the `latest` tag
- 4.0 and 5.0 sections in the upgrade guide, and the Git 2.34.1 requirement of 5.0 in the requirements
- regenerated every reference page from the newest stable tag of its series

Reviewed-on: https://gitea.com/gitea/docs/pulls/599
Reviewed-by: TheFox0x7 <[email protected]>

runner-docs_versions.json

@@ -1,4 +1,6 @@
 [
+    "5",
+    "4",
     "3",
     "2",
     "1",