Bump the dotnet group with 2 updates

Bumps the dotnet group with 2 updates: [dependabot/fetch-metadata](https://github.com/dependabot/fetch-metadata) and [actions/setup-node](https://github.com/actions/setup-node).


Updates `dependabot/fetch-metadata` from 3.0.0 to 3.1.0
- [Release notes](https://github.com/dependabot/fetch-metadata/releases)
- [Commits](dependabot/fetch-metadata@v3.0.0...v3.1.0)

Updates `actions/setup-node` from 6.3.0 to 6.4.0
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@53b8394...48b55a0)

---
updated-dependencies:
- dependency-name: dependabot/fetch-metadata
  dependency-version: 3.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dotnet
- dependency-name: actions/setup-node
  dependency-version: 6.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dotnet
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/dependabot-approve-and-automerge.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - name: Dependabot metadata
         id: metadata
-        uses: dependabot/fetch-metadata@v3.0.0
+        uses: dependabot/fetch-metadata@v3.1.0
         with:
           github-token: "${{ secrets.GITHUB_TOKEN }}"
       - name: Approve a PR

.github/workflows/markdownlint.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 #@v2
     - name: Use Node.js
-      uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f #@v1
+      uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e #@v1
       with:
         node-version: 12.x
     - name: Run Markdownlint