CF worker: remove specific warning admonitions (#203)

In readthedocs/readthedocs-ops#1429 we made the selector
to remove the "external version warning" a lot more specific.

It fixed the original issue, but it resulted in not matching in other themes.
This PR adds extra specific CSS selector for Furo and Book themes.

Closes readthedocs/readthedocs.org#11136

Author: humitos

dockerfiles/force-readthedocs-addons.js

@@ -39,6 +39,10 @@ const badgeOnlyCssAssets =
 const badgeOnlyCssAssetsProxied = 'link[href="/_/static/css/badge_only.css"]';
 const readthedocsExternalVersionWarning =
   "[role=main] > div:first-child > div:first-child.admonition.warning";
+const readthedocsExternalVersionWarningFuroTheme =
+  "[role=main] > div:first-child.admonition.warning";
+const readthedocsExternalVersionWarningBookTheme =
+  "#main-content > div > div > article > div:first-child.admonition.warning";
 const readthedocsFlyout = "div.rst-versions";
 
 // "readthedocsDataParse" is the "<script>" that calls:
@@ -100,6 +104,8 @@ async function handleRequest(request) {
           .on(badgeOnlyCssAssets, new removeElement())
           .on(badgeOnlyCssAssetsProxied, new removeElement())
           .on(readthedocsExternalVersionWarning, new removeElement())
+          .on(readthedocsExternalVersionWarningFuroTheme, new removeElement())
+          .on(readthedocsExternalVersionWarningBookTheme, new removeElement())
           .on(readthedocsFlyout, new removeElement())
           // NOTE: I wasn't able to reliably remove the "<script>" that parses
           // the "READTHEDOCS_DATA" defined previously, so we are keeping it for now.