CI: group dependency updates #572

Problem:
Dependency updates can be noisy. Unmerged dependency updates can block
other updates if the max is reached.

Solution:
- Use dependabot "groups" feature: https://github.blog/2023-08-24-a-faster-way-to-manage-version-updates-with-dependabot/
    - Group updates to "@types/" packages.
    - Group updates to "jest" packages.

ref aws/aws-toolkit-vscode@06507c3

.github/dependabot.yml

@@ -7,6 +7,15 @@ updates:
     directory: "/telemetry/vscode"
     schedule:
       interval: "daily"
+    groups:
+        jest:
+            dependency-type: 'development'
+            patterns:
+                - '*jest'
+        types:
+            dependency-type: 'development'
+            patterns:
+                - '@types/*'
 
   - package-ecosystem: "gradle"
     directory: "/telemetry/jetbrains"