CLI - infisical scan: Honor "gitleaks:ignore" or allow dynamically setting gitleaksAllowSignature

[fkonradmain]

Feature description

Allow dynamically setting gitleaksAllowSignature or filter for both #infisical-scan:ignore and #gitleaks:ignore.

infisical/cli/detect/detect.go

Line 61 in 5ab0c66

gitleaksAllowSignature = "infisical-scan:ignore"

Why would it be useful?

If a user is also using gitleaks and has code tagged via #gitleaks:ignore, these lines would show as leaked secrets when running infisical scan even though they were already handled by the user.