build(protos): Add grpcio-tools as dev dependency

Now available on pypi.devinfra.sentry.io (getsentry/pypi#2138).
Required for proto compilation during development (auto-compile
on import) and CI build steps.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dashed

pyproject.toml

@@ -149,6 +149,7 @@ dev = [
   "covdefaults>=2.3.0",
   "devservices>=1.3.2",
   "docker>=7.1.0",
+  "grpcio-tools>=1.67.0",
   "ephemeral-port-reserve>=1.1.4",
   "flake8>=7.3.0",
   "honcho>=2.0.0",