.github/dependabot.yml: Enable dependabot (#169)

Enables dependabot in this repo.

This GitHub action will automatically create pull requests and
summarize the dependency details. Because it is a pull request,
the CI system will validate the dependency update in the pull
request.

Configures dependabot for:

1. PIP module updates
2. Submodule updates
3. GitHub action updates

After reviewing the submodule updates enabled by the dependabot
change in 6e67d80, we've decided there is more risk than upside
in deviating too far from the submodule versions used in edk2.

Therefore, this change disables submodule updates to prevent them
from being shown in the future.

- [ ] Breaking change?
- Will this change break pre-existing builds or functionality without
action being taken?
  **No**

Verified config in other repos.

N/A - Impacts this repo

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

.github/dependabot.yml

@@ -2,12 +2,13 @@
 # Dependabot configuration file to enable GitHub services for managing and updating
 # dependencies.
 #
-# Copyright (c) Microsoft Corporation.
+# Copyright (c) Microsoft Corporation. All rights reserved.
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 # Please see the documentation for all configuration options:
 # https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
 ##
+
 version: 2
 updates:
   - package-ecosystem: "pip"
@@ -16,10 +17,7 @@ updates:
       interval: "daily"
     commit-message:
       prefix: "pip"
-    reviewers:
-      - "makubacki"
-      - "mdkinney"
-      - "spbrogan"
+
 
   - package-ecosystem: "github-actions"
     directory: "/"
@@ -28,7 +26,3 @@ updates:
       day: "monday"
     commit-message:
       prefix: "GitHub Action"
-    reviewers:
-      - "makubacki"
-      - "mdkinney"
-      - "spbrogan"