ci(dependabot): keep @types/vscode aligned with the engine floor

Dependabot proposes major bumps of @types/vscode that move the types ahead of the minimum VS Code version declared in engines, which breaks the compatibility tests. Ignore major updates for that package.

Author: Michael Gasperini

.github/dependabot.yml

@@ -45,3 +45,8 @@ updates:
     open-pull-requests-limit: 5
     labels:
       - dependencies
+    ignore:
+      # The @types/vscode major tracks the engine floor declared in package.json;
+      # advancing the types ahead of the floor breaks the compatibility tests.
+      - dependency-name: "@types/vscode"
+        update-types: ["version-update:semver-major"]