Allow sending headers to the OpenTelemetry collector

catch → credited slashrsm → .

Added Grafana cloud docs link.

Put up an MR. I tested locally that this doesn't break when the headers aren't set, but hoping @slashrm can test it without actual headers against grafana cloud - if that works, it should also work when we set auth up for core gitlab.

I can confirm that I can pass the headers into the OTEL client, which allows me to authorize with Grafana Cloud.

Backported to 10.2.x as it cherry-picked cleanly and if we need to add headers in the future then it will be useful to have there.

Committed and pushed 4356343b4e to 11.x and 317f5ecdb1 to 10.2.x. Thanks!

longwave → closed merge request !6557

Testing was done by catch in #7

Automatically closed - issue fixed for 2 weeks with no activity.