Update dependency minitest-rails to v8

Author: renovate[bot]

Gemfile.lock

@@ -231,7 +231,7 @@ GEM
     marcel (1.1.0)
     mini_mime (1.1.5)
     mini_portile2 (2.8.9)
-    minitest (5.25.5)
+    minitest (5.26.0)
     minitest-rails (7.2.0)
       minitest (~> 5.20)
       railties (>= 7.2.0, < 8.0.0)