Simplify PHP version determination logic

Author: XSmeets

.github/workflows/docker.yml

@@ -101,23 +101,16 @@ jobs:
         run: |
           tar -xzf simplesamlphp-version-full.tar.gz simplesamlphp-${{ env.VERSION }}/composer.json --strip-components=1
         working-directory: ${{ github.workspace }}
-      - name: Determine latest supported PHP version
+      - name: Determine minimum supported PHP version
         id: php_version
         run: |
           export PATH="$PATH:$HOME/.composer/vendor/bin"
+          # Extract the PHP version constraint from composer.json
           PHP_CONSTRAINT=$(jq -r '.require.php' composer.json)
-          # Fetch all PHP releases from php.net (JSON)
-          RELEASES=$(curl -s 'https://www.php.net/releases/index.php?json&max=1000')
-          # Extract all version fields, reduce to major.minor, deduplicate, and sort
-          VERSIONS=$(echo "$RELEASES" | jq -r '.[] | select(.version != null) | .version' | grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' | awk -F. '{print $1 "." $2}' | sort -Vu)
-          # Use composer/semver to find the highest matching version
-          MATCH=$(echo "$VERSIONS" | xargs -I{} semver "$PHP_CONSTRAINT" {} | tail -n1)
-          if [ -z "$MATCH" ]; then
-            # fallback to highest version if no match
-            PHP_VERSION=$(echo "$VERSIONS" | tail -n1)
-          else
-            PHP_VERSION=$MATCH
-          fi
+          # Use composer/semver to get the minimum version that satisfies the constraint
+          MIN_VERSION=$(semver "$PHP_CONSTRAINT" | head -n1)
+          # Reduce to major.minor (e.g., 8.2 from 8.2.23)
+          PHP_VERSION=$(echo "$MIN_VERSION" | awk -F. '{print $1 "." $2}')
           echo "PHP_VERSION=$PHP_VERSION" >> $GITHUB_ENV
           echo "php_version=$PHP_VERSION" >> $GITHUB_OUTPUT
         working-directory: ${{ github.workspace }}