stop using the word 'just'

Everywhere. In documentation and code comments.

It is almost never a good word and almost always a filler that should be
avoided.

Closes #20793

docs/examples/imap-lsub.c

@@ -49,7 +49,7 @@ int main(void)
     curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
     curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
 
-    /* This is just the server URL */
+    /* This is the server URL */
     curl_easy_setopt(curl, CURLOPT_URL, "imap://imap.example.com");
 
     /* Set the LSUB command. Note the syntax is similar to that of a LIST