fix(tests): remove integration tests that depend on deleted Remote API classes

The Remote API classes (OC\Remote\* and OCP\Remote\*) were removed in
#60953, but the remoteapi Behat integration suite was not updated. This
caused fatal PHP errors when Behat tried to bootstrap RemoteContext,
breaking the integration test run on master.

Remove RemoteContext.php, remote.feature, and the remoteapi suite entry
in behat.yml since there is nothing left to test.

Assisted-by: ClaudeCode:claude-sonnet-4-6
Signed-off-by: Anna Larch <anna@nextcloud.com>

Author: miaulalala

build/integration/config/behat.yml

@@ -254,19 +254,6 @@ default:
               - admin
               - admin
             regular_user_password: 123456
-    remoteapi:
-      paths:
-        - "%paths.base%/../remoteapi_features"
-      contexts:
-        - FeatureContext:
-            baseUrl: http://localhost:8080/ocs/
-            admin:
-              - admin
-              - admin
-            regular_user_password: 123456
-        - RemoteContext:
-            remote: http://localhost:8080
-
     ratelimiting:
       paths:
         - "%paths.base%/../ratelimiting_features"