Enable PHP 7.2-8.1 compat

[iansltx]

No description provided.

[iansltx]

Bumping this as I believe all feedback has been responded to.

[kenjis]

On PHP 7.3 and 7.4

There was 1 error:

1) Aura\Sql\ConnectionLocatorTest::testNullDefault
Declaration of Aura\Sql\AbstractExtendedPdo::prepare($query, array $options = Array): PDOStatement should be compatible with PDO::prepare($statement, $options = NULL)

/home/runner/work/Aura.Sql/Aura.Sql/src/AbstractExtendedPdo.php:26
/home/runner/work/Aura.Sql/Aura.Sql/src/ExtendedPdo.php:22
/home/runner/work/Aura.Sql/Aura.Sql/tests/ConnectionLocatorTest.php:24