Upgrade xk6-browser to v1.2.1

[ankur22]

What?

This upgrades the xk6-browser extension to v1.2.1 in k6.

Why?

Upgrade the extension in preparation for an upcoming release.

Checklist

• I have performed a self-review of my code.
• I have added tests for my changes.
• I have run linter locally (make lint) and all checks pass.
• I have run tests locally (make tests) and all tests pass.
• I have commented on my code, particularly in hard-to-understand areas.

Related PR(s)/Issue(s)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (e603a49) 73.20% compared to head (a493b85) 73.20%.

❗ Current head a493b85 differs from pull request most recent head 1db825a. Consider uploading reports for the commit 1db825a to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3476   +/-   ##
=======================================
  Coverage   73.20%   73.20%           
=======================================
  Files         267      267           
  Lines       20083    20083           
=======================================
  Hits        14701    14701           
  Misses       4468     4468           
  Partials      914      914           

Flag	Coverage Δ
ubuntu	73.14% <ø> (-0.01%)	⬇️
windows	73.06% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.