build: 🔧 fix PHP version retrieval in CI workflow

* Updated the method for retrieving the PHP version in the CI workflow.
* Changed from using 'PHP_VERSION=' to 'ARG PHP_VERSION=' for better accuracy.

Author: svasek

.github/workflows/docker-image.yml

@@ -57,7 +57,7 @@ jobs:
           if [[ -n "${{ github.event.inputs.version }}" ]]; then
             export PHPVERSION="${{ github.event.inputs.version }}"
           else
-            export PHPVERSION=$(grep 'PHP_VERSION=' Dockerfile | cut -d'=' -f2)
+            export PHPVERSION=$(grep -m1 '^ARG PHP_VERSION=' Dockerfile | cut -d'=' -f2)
           fi
           echo "full_version=${PHPVERSION}" >> $GITHUB_OUTPUT
           echo "mino_version=${PHPVERSION%.*}" >> $GITHUB_OUTPUT

Dockerfile

@@ -1,7 +1,9 @@
-ARG PHP_VERSION=8.5.4 \
-    ALPINE_VERSION
+ARG PHP_VERSION=8.5.4
+ARG ALPINE_VERSION
 
 FROM php:${PHP_VERSION}-fpm-alpine
+ARG PHP_VERSION
+ARG ALPINE_VERSION
 LABEL maintainer="Milos Svasek <[email protected]>" \
       alpine.version="${ALPINE_VERSION}" \
       php.version="${PHP_VERSION}"