switch from setup-beam to pre-built elixir-base container image

.forgejo/workflows/ci.yml

@@ -10,6 +10,7 @@ jobs:
   quality:
     name: Build and test
     runs-on: ubuntu-24.04
+    container: git.mcintire.me/graham/elixir-base:latest
     services:
       postgres:
         image: postgis/postgis:17-3.5
@@ -36,13 +37,6 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Set up Elixir
-        uses: http://forgejo:3000/graham/setup-beam@v1
-        with:
-          version-type: strict
-          elixir-version: '1.20.2'
-          otp-version: '29.0'
-
       - name: Restore dependency and build caches
         uses: https://code.forgejo.org/actions/cache@v4
         with:
@@ -53,11 +47,6 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-mix-
 
-      - name: Install Hex and Rebar
-        run: |
-          mix local.hex --force
-          mix local.rebar --force
-
       - name: Fetch dependencies
         run: mix deps.get
 
@@ -82,6 +71,7 @@ jobs:
   dialyzer:
     name: Dialyzer
     runs-on: ubuntu-24.04
+    container: git.mcintire.me/graham/elixir-base:latest
     env:
       MIX_ENV: dev
 
@@ -95,13 +85,6 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Set up Elixir
-        uses: http://forgejo:3000/graham/setup-beam@v1
-        with:
-          version-type: strict
-          elixir-version: '1.20.2'
-          otp-version: '29.0'
-
       - name: Restore dependency and build caches
         uses: https://code.forgejo.org/actions/cache@v4
         with:
@@ -112,11 +95,6 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-dialyzer-
 
-      - name: Install Hex and Rebar
-        run: |
-          mix local.hex --force
-          mix local.rebar --force
-
       - name: Fetch dependencies
         run: mix deps.get