sysutils/tflint: Update to 0.50.2

Bug fixes:
Fix a bug where auto-fixed code could not be retrieved via GetFile API

Chores:
Bump github.com/cloudflare/circl from 1.3.3 to 1.3.7
Bump golang.org/x/oauth2 from 0.15.0 to 0.16.0

Approved by: dbaio(mentor), garga(mentor)
Differential Revision: https://reviews.freebsd.org/D43588