feat(federation): add scenario-mastodon setup and teardown (#1274)

2/5 taken out of #1269

This patch adds the setup and teardown of Mastodon for use in the end-to-end tests

Co-Authored-By: zam <mirco.zachmann@meissa.de>
Co-Authored-By: erik <erik.seiert@meissa-gmbh.de>
Co-Authored-By: Michael Jerger <michael.jerger@meissa-gmbh.de>

Reviewed-on: https://code.forgejo.org/forgejo/end-to-end/pulls/1274
Reviewed-by: earl-warren <earl-warren@noreply.code.forgejo.org>
Reviewed-by: Beowulf <beowulf@noreply.code.forgejo.org>
Co-authored-by: famfo <famfo@famfo.xyz>
Co-committed-by: famfo <famfo@famfo.xyz>

federation/federation.sh

@@ -78,6 +78,7 @@ function test_federation() {
         # NOTE: newline seperated, not comma :>
         scenarios=(
             "star 7.1"
+            "mastodon 14.0"
         )
 
         for scenario_version_str in "${scenarios[@]}"; do