ci(phpunit): install core patches that have no shopware/production tag

The newest shopware/core in ~6.6.0 is 6.6.10.31, but shopware/production
is only tagged up to 6.6.10.30, so create-project failed. Install the newest
template inside the constraint and require the resolved core version on top.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/plugin-checks.yml

@@ -110,6 +110,7 @@ jobs:
           test -n "$VERSION" || { echo "::error::could not resolve a Shopware version for ${CONSTRAINT}"; exit 1; }
           echo "Shopware ${VERSION} (constraint ${CONSTRAINT})"
           echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+          echo "constraint=${CONSTRAINT}" >> "$GITHUB_OUTPUT"
       # Project (vendor/, phpunit, config) and the installed database as a SQL dump. Neither depends on the plugin.
       - name: Restore Shopware project and database
         id: shopware
@@ -125,8 +126,13 @@ jobs:
         if: steps.shopware.outputs.cache-hit != 'true'
         run: |
           set -e
-          composer create-project "shopware/production:${{ steps.sw.outputs.version }}" shopware --no-interaction --no-scripts
-          composer require --dev phpunit/phpunit:^10 --no-interaction --no-scripts -d shopware
+          # shopware/production pins one exact core version and is not tagged for every core patch
+          # (e.g. core 6.6.10.31, template only up to 6.6.10.30): take the newest template inside the
+          # constraint, then require the resolved core version on top of it.
+          composer create-project "shopware/production:${{ steps.sw.outputs.constraint }}" shopware --no-interaction --no-scripts --no-install
+          composer require "shopware/core:${{ steps.sw.outputs.version }}" --no-update -d shopware
+          composer require --dev phpunit/phpunit:^10 --no-update -d shopware
+          composer update -W --no-interaction --no-scripts -d shopware
       - name: Ensure the MariaDB client
         run: |
           command -v mariadb-dump >/dev/null || command -v mysqldump >/dev/null && exit 0