Bump explorer rollout to 30%

Author: vinistock

vscode/src/common.ts

@@ -88,7 +88,7 @@ export const SUPPORTED_LANGUAGE_IDS = ["ruby", "erb"];
 export const FEATURE_FLAGS = {
   tapiocaAddon: 1.0,
   launcher: 0.1,
-  fullTestDiscovery: 0.15,
+  fullTestDiscovery: 0.3,
 };
 
 type FeatureFlagConfigurationKey = keyof typeof FEATURE_FLAGS | "all";