fix(mirrors): use 'rg' for regular expressions on Xiaomi links

 * This should ultimately resolve issues where the best mirror for
   'cdnorg' got calculated, even if we specifically told the script not to.

 * 'ripgrep' should be also faster, but in this case it brings close to
    zero improvements. This was rather done for simplicity and uniformity,
    considering we use 'rg' in most occasions.

extract_and_push.sh

@@ -137,7 +137,7 @@ else
         # For Xiaomi: replace '${URL}' with (one of) the fastest mirror
         *"d.miui.com"*)
             # Do not run this loop in case we're already using one of the reccomended mirrors
-            if [[ "$(echo "${URL}" | grep -qE '(cdnorg|bkt-sgp-miui-ota-update-alisgp)')" -eq 0 ]]; then
+            if ! echo "${URL}" | rg -q 'cdnorg|bkt-sgp-miui-ota-update-alisgp'; then
                 # Set '${URL_ORIGINAL}' and '${FILE_PATH}' in case we might need to roll back
                 URL_ORIGINAL=$(echo "${URL}" | sed -E 's|(https://[^/]+).*|\1|')
                 FILE_PATH=${URL#*d.miui.com/}