try to fix GH action (#14)

Author: egze

.github/workflows/elixir.yml

@@ -7,33 +7,32 @@ name: Elixir CI
 
 on:
   push:
-    branches: [ "main" ]
+    branches: ["main"]
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 permissions:
   contents: read
 
 jobs:
   build:
-
     name: Build and test
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
-    - uses: actions/checkout@v4
-    - name: Set up Elixir
-      uses: erlef/setup-beam@61e01a43a562a89bfc54c7f9a378ff67b03e4a21 # v1.16.0
-      with:
-        elixir-version: '1.17.3' # [Required] Define the Elixir version
-        otp-version: '27.1'      # [Required] Define the Erlang/OTP version
-    - name: Restore dependencies cache
-      uses: actions/cache@v3
-      with:
-        path: deps
-        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
-        restore-keys: ${{ runner.os }}-mix-
-    - name: Install dependencies
-      run: mix deps.get
-    - name: Run tests
-      run: mix test
+      - uses: actions/checkout@v4
+      - name: Set up Elixir
+        uses: erlef/setup-beam@v1
+        with:
+          elixir-version: "1.17.3" # [Required] Define the Elixir version
+          otp-version: "27.1" # [Required] Define the Erlang/OTP version
+      - name: Restore dependencies cache
+        uses: actions/cache@v3
+        with:
+          path: deps
+          key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-mix-
+      - name: Install dependencies
+        run: mix deps.get
+      - name: Run tests
+        run: mix test