feat!: Update GraphQL span name convention

[kaylareopelle]

Fixes #1361

Changes

Due to concerns about high cardinality with the current span name format, use only the graphql.operation.type attribute for the span name. The higher cardinality attribute, graphql.operation.name can still be used in queries, as it is an attribute on the span. The original fallback span name, GraphQL Operation, is preserved.

Merge requirement checklist

• [X] CONTRIBUTING.md guidelines followed.
• [X] Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• [X] schema-next.yaml updated with changes to existing conventions. (I don't think this needs to be updated because it's a span name and not an attribute)

[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 7 days.

[kaylareopelle]

It seems like the wayback machine is down at the moment, causing the markdown-link-check job to fail: https://github.com/open-telemetry/semantic-conventions/actions/runs/11263374842/job/31321102055?pr=1389#step:4:10