Fixes `diffs` column type when JSON type is supported #289

Job	Run time
Runs PHP-CS-Fixer to check for CS issues, and validates composer.json	39s
Tests PHP 8.0, Symfony 5.*, sqlite	1m 40s
Tests PHP 8.0, Symfony 5.*, mysql	2m 22s
Tests PHP 8.0, Symfony 5.*, pgsql	1m 39s
Tests PHP 8.0, Symfony 6.*, sqlite	1m 43s
Tests PHP 8.0, Symfony 6.*, mysql	2m 6s
Tests PHP 8.0, Symfony 6.*, pgsql	2m 13s
Tests PHP 8.1, Symfony 5.*, sqlite	1m 58s
Tests PHP 8.1, Symfony 5.*, mysql	2m 11s
Tests PHP 8.1, Symfony 5.*, pgsql	1m 47s
Tests PHP 8.1, Symfony 6.*, sqlite	1m 23s
Tests PHP 8.1, Symfony 6.*, mysql	2m 43s
Tests PHP 8.1, Symfony 6.*, pgsql	1m 49s
Tests PHP 8.2, Symfony 5.*, sqlite	1m 38s
Tests PHP 8.2, Symfony 5.*, mysql	2m 12s
Tests PHP 8.2, Symfony 5.*, pgsql	1m 35s
Tests PHP 8.2, Symfony 6.*, sqlite	2m 6s
Tests PHP 8.2, Symfony 6.*, mysql	2m 10s
Tests PHP 8.2, Symfony 6.*, pgsql	2m 11s
Upload coverage to Codecov	7s
	36m 12s

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