Secret Detection: Tighten regex for Social Security Numbers (SSNs)

From @miguel.rodriguez4 in #345453 (comment 842601583):

I would love to suggest a better regex for detecting valid social security numbers.

regex = "^(?!666|000|9\\d{2})\\d{3}-(?!00)\\d{2}-(?!0{4})\\d{4}$"

Regex explanation: https://www.geeksforgeeks.org/how-to-validate-ssn-social-security-number-using-regular-expression/

Social Security Number Randomization: https://www.ssa.gov/employer/randomization.html

Social Security Number Randomization FAQs? See "Will SSN randomization assign group number 00 or serial number 0000?" SSN randomization will not assign group number 00 or serial number 0000. SSNs containing group number 00 or serial number 0000 will continue to be invalid.