(deps): Bump gitreleasemanager.tool from 0.19.0 to 0.20.0 in /build

Bumps [gitreleasemanager.tool](https://github.com/GitTools/GitReleaseManager) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/GitTools/GitReleaseManager/releases)
- [Changelog](https://github.com/GitTools/GitReleaseManager/blob/develop/GitReleaseManager.yaml)
- [Commits](GitTools/GitReleaseManager@0.19.0...0.20.0)

---
updated-dependencies:
- dependency-name: gitreleasemanager.tool
  dependency-version: 0.20.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "gitreleasemanager.tool": {
-      "version": "0.19.0",
+      "version": "0.20.0",
       "commands": [
         "dotnet-gitreleasemanager"
       ]