[LOW] CVE-2020-5255: Prevent cache poisoning via a Response Content-Type header

PKSA-5vcz-b73r-4b7v CVE-2020-5255 GHSA-mcx4-f5f5-4859

Affected package: symfony/symfony

Affected version: >=4.4.0,<4.4.7|>=5.0.0,<5.0.7

Reported by:
GitHub, FriendsOfPHP/security-advisories