Bump erlef/setup-beam from 1.19.0 to 1.20.2

Bumps [erlef/setup-beam](https://github.com/erlef/setup-beam) from 1.19.0 to 1.20.2.
- [Release notes](https://github.com/erlef/setup-beam/releases)
- [Commits](erlef/setup-beam@8aa8a85...6389fe5)

---
updated-dependencies:
- dependency-name: erlef/setup-beam
  dependency-version: 1.20.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
 
-      - uses: erlef/setup-beam@8aa8a857c6be0daae6e97272bb299d5b942675a4
+      - uses: erlef/setup-beam@6389fe58dcb1ee91fd829c7c65bf8771b06dacc4
         with:
           otp-version: "26.2"
           gleam-version: "1.10.0"