ci: simplify hex authentication using HEX_API_KEY env var

rebar3_hex natively supports HEX_API_KEY environment variable for
authentication. Remove the manual hex.config creation step and rely
on the built-in env var support instead.

Author: codeadict

.github/workflows/release.yml

@@ -44,20 +44,15 @@ jobs:
           test -f doc/index.html || (echo "doc/index.html not found" && exit 1)
           echo "Documentation built successfully"
 
-      - name: Configure Hex authentication
-        run: |
-          mkdir -p ~/.config/rebar3
-          cat > ~/.config/rebar3/hex.config <<EOF
-          {api_key, <<"$HEX_API_KEY">>}.
-          EOF
-        env:
-          HEX_API_KEY: ${{ secrets.HEX_API_KEY }}
-
       - name: Publish to Hex
         run: rebar3 hex publish --yes
+        env:
+          HEX_API_KEY: ${{ secrets.HEX_API_KEY }}
 
       - name: Publish docs to Hex
         run: rebar3 hex docs publish --yes
+        env:
+          HEX_API_KEY: ${{ secrets.HEX_API_KEY }}
 
       - name: Extract release notes from CHANGELOG
         id: changelog