Psalm: switch from Phive to Composer

This switches the installation method for Psalm from Phive to Composer, while still using a Phar file for running Psalm.

Includes:
* Removing Psalm from the Phive configuration.
* Adding Psalm to the Composer configuration. Includes upgrading from version `3.11.2` to version `4.8.1`.
* Adjusting the script used in the `Makefile`.
    👉 Please verify and test this as things work differently on different OS-es and this should work for you.
* Adjusting the GH Actions script to use the Composer installed version of Psalm.

Note: due to the committed `composer.lock` file, Psalm will not automatically upgrade when newer versions are available.

Refs:
* https://github.com/vimeo/psalm/releases
* https://github.com/psalm/phar/releases

composer.json

@@ -21,7 +21,8 @@
         "ext-filter": "*"
     },
     "require-dev": {
-        "mockery/mockery": "~1.3.2"
+        "mockery/mockery": "~1.3.2",
+        "psalm/phar": "^4.8"
     },
     "autoload": {
         "psr-4": {