[v10.0/forgejo] fix: always set stripped slashes on http request (#6884)

**Backport:** https://codeberg.org/forgejo/forgejo/pulls/6866

- The middleware that takes care of normalizing `//user2/////repo1` to `/user2/repo1` would only set the normalized value to the Chi (Forgejo's http router) `RoutePath` field, so Chi would correctly do the routing. However not all components in Forgejo (like Forgejo's `context` module) rely on Chi to get this updated path and some still rely on the value of `(http.Request).URL.Path`, so always set the normalized value to the http request.
- Adjusted unit test.
- Resolves forgejo/forgejo#6822
- The related issue was caused by
751a3da979/services/context/context.go (L115)
using the value of the http request on not that was set in the Chi context.

Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6884
Reviewed-by: Otto <otto@codeberg.org>
Co-authored-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
Co-committed-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>

routers/common/middleware.go

@@ -92,10 +92,9 @@ func stripSlashesMiddleware(next http.Handler) http.Handler {
 			prevWasSlash = chr == '/'
 		}
 
-		if rctx == nil {
-			req.URL.Path = sanitizedPath.String()
-		} else {
-			rctx.RoutePath = sanitizedPath.String()
+		req.URL.Path = sanitizedPath.String()
+		if rctx != nil {
+			rctx.RoutePath = req.URL.Path
 		}
 		next.ServeHTTP(resp, req)
 	})