Limit write access to Profiling SIG meeting notes

[florianl]

The meeting notes for the Profiling SIG were repeatedly compromised: they were deleted and replaced with malicious content - see https://cloud-native.slack.com/archives/C03J794L0BV/p1771427070939619 and https://cloud-native.slack.com/archives/C03J794L0BV/p1770818982983299

To prevent unauthorized and anonymous modifications, please restrict write access to this document.

This was also discussed in the last Profiling SIG meeting - see 2026-02-19

FYI: @jsuereth @open-telemetry/profiling-maintainers

[mx-psi]

Assigning @mtwo as the GC liaison