Grafana Tempo 2.10 adds missing-attribute queries and production-ready vParquet5

Grafana Tempo 2.10 adds TraceQL options for locating absent attributes and integer boundaries, along with changes to metrics generation and block encoding. TraceQL’s `= nil` check matches attributes that are missing or null, while `!= nil` can test for a non-null value; `minInt` and `maxInt` represent the supported integer limits. TraceQL also supports querying spans by the number of direct child operations they trigger, including queries for high child counts. Entity-based limiting gives the metrics-generator an alternative to series-based limits, keeping complete metrics for each logical entity instead of randomly removing series. When limits are reached, it creates overflow series with the `metric_overflow="true"` label rather than discarding data. vParquet5 is production-ready, but vParquet4 remains the default block format in this release. vParquet5 adds array and event-level support for dedicated columns and virtual span row numbers that speed queries filtering resource attributes.