Update Dependabot configuration under /typespec/ (radius-project#8055)

# Description

Updating Dependabot configuration under /typespec/ so that Major and
Minor updates should not trigger Dependabot pull requests (PRs) for
regular version updates.
ref link: [Dependabot
Config](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#example-3)
## Type of change

- This pull request is a minor refactor, code cleanup, test improvement,
or other maintenance task and doesn't change the functionality of Radius
(issue link optional).

Fixes: #issue_number

## Contributor checklist
Please verify that the PR meets the following requirements, where
applicable:

- [ ] An overview of proposed schema changes is included in a linked
GitHub issue.
- [ ] A design document PR is created in the [design-notes
repository](https://github.com/radius-project/design-notes/), if new
APIs are being introduced.
- [ ] If applicable, design document has been reviewed and approved by
Radius maintainers/approvers.
- [ ] A PR for the [samples
repository](https://github.com/radius-project/samples) is created, if
existing samples are affected by the changes in this PR.
- [ ] A PR for the [documentation
repository](https://github.com/radius-project/docs) is created, if the
changes in this PR affect the documentation or any user facing updates
are made.
- [ ] A PR for the [recipes
repository](https://github.com/radius-project/recipes) is created, if
existing recipes are affected by the changes in this PR.

---------

Signed-off-by: lakshmimsft <[email protected]>

.github/dependabot.yml

@@ -32,3 +32,10 @@ updates:
     directory: "/typespec/"
     schedule:
       interval: "weekly"
+    groups:
+      typespec:
+        applies-to: version-updates
+        patterns:
+        - "*"        # Matches all dependencies
+        update-types:
+        - "patch"    # Only allow patch updates for regular version updates