Don't show AbortErrors on logout (#29639) (#29667)

Backport #29639.

When logging out of Gitea, a error toast can be seen for a split second.
I don't know why or how it happens but I found it it's an `AbortError`
(related to
[AbortController#abort](https://developer.mozilla.org/en-US/docs/Web/API/AbortController/abort)),
so let's hide it.

web_src/js/features/common-global.js

@@ -101,9 +101,11 @@ async function fetchActionDoRequest(actionElem, url, opt) {
       showErrorToast(`server error: ${resp.status}`);
     }
   } catch (e) {
-    console.error('error when doRequest', e);
     actionElem.classList.remove('is-loading', 'small-loading-icon');
-    showErrorToast(i18n.network_error);
+    if (e.name !== 'AbortError') {
+      console.error('error when doRequest', e);
+      showErrorToast(i18n.network_error);
+    }
   }
 }