chore: remove non-existing tests

Signed-off-by: Bart Jaskulski <bjaskulski@protonmail.com>

phpunit-unit.xml

-<phpunit bootstrap="tests/unit/bootstrap.php">
-    <testsuites>
-        <testsuite>
-            <directory prefix="test-" suffix=".php">./tests/unit/</directory>
-        </testsuite>
-    </testsuites>
-
-    <filter>
-        <whitelist>
-            <directory suffix=".php">classes</directory>
-        </whitelist>
-    </filter>
-
-    <logging>
-        <log type="junit" target="build-coverage/report.junit.xml"/>
-        <log type="coverage-html" target="build-coverage/coverage" charset="UTF-8" yui="true" highlight="true"/>
-        <log type="coverage-text" target="build-coverage/coverage.txt"/>
-        <log type="coverage-clover" target="build-coverage/clover.xml"/>
-    </logging>
-
-</phpunit>
\ No newline at end of file

tests/unit/bootstrap.php

-<?php
-/**
- * PHPUnit bootstrap file
- */
-
-require_once __DIR__ . '/../../vendor/autoload.php';
-
-error_reporting( E_ALL );
-
-if ( getenv( 'PLUGIN_PATH' ) !== false ) {
-	define( 'PLUGIN_PATH', getenv( 'PLUGIN_PATH' ) );
-} else {
-	define( 'PLUGIN_PATH', __DIR__ . DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR );
-}
-
-if ( getenv( 'ABSPATH' ) !== false ) {
-	define( 'ABSPATH', getenv( 'ABSPATH' ) );
-} else {
-	define( 'ABSPATH', PLUGIN_PATH . '..' . DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR );
-}
-
-WP_Mock::setUsePatchwork( true );
-WP_Mock::bootstrap();