ci: group go.opentelemetry.io deps together with other otel deps

[jharvey10]

Group go.opentelemetry.io updates into the same PR group as github.com/open-telemetry/opentelemetry-collector-contrib

This should reduce a lot of the size of the non-open telemetry minor/patch updates.

[ptodev]

Do you think we should exclude otel dependencies from renovate altogether? We only update them manually anyway. Certainly OTel component updates need to be manual.

[jharvey10]

@ptodev That's effectively what this PR will do :) The "dependencyDashboardApproval": true line will not allow PRs for these deps to get auto-created. They'll still show up on the dependency dashboard grouped together and show us what versions are available, but it won't take any action on them unless we initiate it.