Update docs for old mautrix bridges for Facebook and Instagram: remove anchor links to the deleted files

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-bridge-mautrix-facebook.md

@@ -76,7 +76,7 @@ ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-use
 
 To use the bridge, you need to start a chat with `@facebookbot:example.com` (where `example.com` is your base domain, not the `matrix.` domain).
 
-Send `login YOUR_FACEBOOK_EMAIL_ADDRESS` to the bridge bot to enable bridging for your Facebook Messenger account. You can learn more here about authentication from the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/python/facebook/authentication.html).
+Send `login YOUR_FACEBOOK_EMAIL_ADDRESS` to the bridge bot to enable bridging for your Facebook Messenger account.
 
 If you run into trouble, check the [Troubleshooting](#troubleshooting) section below.
 

docs/configuring-playbook-bridge-mautrix-instagram.md

@@ -64,5 +64,3 @@ ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-use
 To use the bridge, you need to start a chat with `@instagrambot:example.com` (where `example.com` is your base domain, not the `matrix.` domain).
 
 Send `login YOUR_INSTAGRAM_EMAIL_ADDRESS YOUR_INSTAGRAM_PASSWORD` to the bridge bot to enable bridging for your instagram/Messenger account.
-
-You can learn more here about authentication from the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/python/instagram/authentication.html).