Stable autoloader suffix for checksum

Author: ondrejmirtes

.github/workflows/phar.yml

@@ -53,12 +53,18 @@ jobs:
         working-directory: "compiler"
         run: "php bin/prepare"
 
+      - name: "Set autoloader suffix"
+        run: "composer config autoloader-suffix PHPStanChecksum"
+
       - name: "Compile PHAR for checksum"
         working-directory: "compiler/build"
         run: "php box.phar compile --no-parallel"
         env:
           PHAR_CHECKSUM: "1"
 
+      - name: "Unset autoloader suffix"
+        run: "composer config autoloader-suffix --unset"
+
       - name: "Save checksum"
         id: "checksum"
         run: echo "::set-output name=md5::$(md5sum tmp/phpstan.phar)"