Bump Traffic Cop to v3.0.0 (Fixes #14086)

[alexgibson]

One-line summary

• Bumps Traffic Cop to v3.0.0 (which removes use of cookies).
• Removes bedrock code that would try to read the TC custom referrer cookie (we can revisit this in the future to add back to bedrock if we find we need it).
• Removes redundant id and cookieExpires properties from TC experiment configs.

Issue / Bugzilla link

#14086

Testing

First run make preflight.

The following URLs should still redirect to a variation as normal:

• http://localhost:8000/en-US/products/vpn/
• http://localhost:8000/en-US/firefox/119.0/whatsnew/
• http://localhost:8000/en-US/firefox/welcome/15/

The main difference is that each time you hit one of the original URLs above, you may get redirected to a different version than before (since we no longer set a cookie to remember).

[craigcook]

👮