- update to 1.21.0:
* Fix `SumAggregation`  (#3390)
* Fix handling of empty metric collection cycles (#3335)
* Fix error when no LoggerProvider configured for
LoggingHandler (#3423)
* Make `opentelemetry_metrics_exporter` entrypoint support pull
exporters (#3428)
* Allow instrument names to have '/' and up to 255 characters
(#3442)
* Do not load Resource on sdk import (#3447)
* Update semantic conventions to version 1.21.0 (#3251)
* Add missing schema_url in global api for logging and metrics
(#3251)
* Prometheus exporter support for auto instrumentation (#3413)
* Modify Prometheus exporter to translate non-monotonic Sums
into Gauges (#3306)
* Update the body type in the log ($3343)
* Add max_scale option to Exponential Bucket Histogram
Aggregation (#3323)
* Use BoundedAttributes instead of raw dict to extract
attributes from LogRecord (#3310)
* Support dropped_attributes_count in LogRecord and exporters
(#3351)
* Add unit to view instrument selection criteria (#3341)
* Upgrade opentelemetry-proto to 0.20 and regen #3355)
* Include endpoint in Grpc transient error warning #3362)
* Fixed bug where logging export is tracked as trace #3375)
* Select histogram aggregation with an environment variable
* Move Protobuf encoding to its own package (#3169)
* Add experimental feature to detect resource detectors in auto