Do not report detekt LargeClass issues on test classes (#7713)

detekt's default configuration excludes test source sets from
`TooManyFunctions` and `StringLiteralDuplication`, but not from
`LargeClass`, so large test classes were reported and had to carry a
`@Suppress("LargeClass")` annotation.

Add the same kind of exclusion to the `LargeClass` rule in
`tools/detekt/detekt.yml` and remove the 24 now-redundant suppressions
from test files. The two remaining suppressions are in production code,
where the rule still applies.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

tools/detekt/detekt.yml

@@ -175,6 +175,8 @@ complexity:
     active: true
   LargeClass:
     active: true
+    # Do not report large test classes.
+    excludes: [ '**/test/**', '**/androidTest/**' ]
 
 naming:
   VariableNaming: