chore(deps): group @salesforce/* dependabot updates

Add dependabot group 'salesforce-deps' so minor/patch updates for @salesforce/* packages (templates, ts-types, vscode-i18n, core, etc.) are batched into one PR.

Made-with: Cursor

Author: k-j-kim

.github/dependabot.yml

@@ -18,6 +18,10 @@ updates:
       day: 'wednesday'
       time: '06:00'
       timezone: 'America/Los_Angeles'
+    groups:
+      salesforce-deps:
+        patterns:
+          - '@salesforce/*'
     ignore:
       - dependency-name: '*'
         update-types: ['version-update:semver-major']