chore: fix broken gql test service

[metal-messiah]

Point the graphql tests to our internal testing service with a new mocked endpoint instead of relying on a demo service, which has recently gone down and caused test failures.

Overview

Related Issue(s)

Testing

graphql-metadata.e2e.js should now pass

[github-actions]

Supportability Metric Usage Changes:

No matching changes found

Supportability Metrics .md File Changes:

supportability_metrics.md was changed? false

New supportability metrics require changes to supportability_metrics.md, as well as a new PR to Angler. Please ensure an Angler PR is created and linked to this PR.

[github-actions]

Asset Size Report

Merging this pull request will result in the following asset size changes:

Agent	Asset	Previous Size	New Size	Diff
lite	loader	24.97 kB / 9.47 kB (gzip)	24.97 kB / 9.47 kB (gzip)	0% / 0% (gzip)
lite	async-chunk	52.6 kB / 17.45 kB (gzip)	52.6 kB / 17.45 kB (gzip)	0% / 0% (gzip)
pro	loader	52.91 kB / 18.61 kB (gzip)	52.91 kB / 18.61 kB (gzip)	0% / 0% (gzip)
pro	async-chunk	92 kB / 28.52 kB (gzip)	92 kB / 28.52 kB (gzip)	0% / 0% (gzip)
spa	loader	61.66 kB / 21.31 kB (gzip)	61.66 kB / 21.31 kB (gzip)	0% / 0% (gzip)
spa	async-chunk	116.63 kB / 35.49 kB (gzip)	116.63 kB / 35.49 kB (gzip)	0% / 0% (gzip)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.61%. Comparing base (375c37f) to head (f1c90c3).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1498   +/-   ##
=======================================
  Coverage   87.61%   87.61%           
=======================================
  Files         197      197           
  Lines        7761     7761           
  Branches     1563     1563           
=======================================
  Hits         6800     6800           
  Misses        826      826           
  Partials      135      135           

Flag	Coverage Δ
unit-tests	78.71% <ø> (ø)

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[metal-messiah]

smoke test in progress - https://github.com/newrelic/newrelic-browser-agent/actions/runs/15571159088

[ellisong]

LGTM