Prepare release 1.9.0 (#734)

Co-authored-by: Robert Pająk <[email protected]>

Author: lmolkova

CHANGELOG.md

@@ -4,16 +4,28 @@ The full list of changes can be found in the compare view for the respective rel
 
 ## Unreleased
 
+### Added
+
 ### Changed
 
-- profiles: clarify dictionary guidelines: duplicates and other restrictions. [#732](https://github.com/open-telemetry/opentelemetry-proto/pull/732)
+### Fixed
+
+### Removed
+
+## 1.9.0 - 2025-10-31
+
+### Added
+
 - profiles: drop field profile.comment_strindices. [#729](https://github.com/open-telemetry/opentelemetry-proto/pull/729)
 - profiles: clarify the original payload field comments. [#722](https://github.com/open-telemetry/opentelemetry-proto/pull/722)
 - profiles: add a note about cardinality implications for attribute values. [#713](https://github.com/open-telemetry/opentelemetry-proto/pull/713)
-- profiles: rename line -> lines and sample -> samples since they are repeated fields. [#712](https://github.com/open-telemetry/opentelemetry-proto/pull/712)
 
 ### Changed
 
+- profiles: clarify dictionary guidelines: duplicates and other restrictions. [#732](https://github.com/open-telemetry/opentelemetry-proto/pull/732)
+- profiles: clarify the original payload field comments. [#722](https://github.com/open-telemetry/opentelemetry-proto/pull/722)
+- profiles: rename line -> lines and sample -> samples since they are repeated fields. [#712](https://github.com/open-telemetry/opentelemetry-proto/pull/712)
+- profiles: document more explicitly the dictionary zero element requirement. [#711](https://github.com/open-telemetry/opentelemetry-proto/pull/711)
 - all: drop attribute values restrictions. [#707](https://github.com/open-telemetry/opentelemetry-proto/pull/707)<br>
   ⚠️ **IMPORTANT**: OTLP consumers are expected to accept attribute values that were previously considered invalid.
   All attributes can now contain:
@@ -22,8 +34,14 @@ The full list of changes can be found in the compare view for the respective rel
   - array values different than array of string values, bool values, int values, double values,
   - kvlist values.
 
+### Fixed
+
+- all: fix schema_url comments to include scope field coverage. [#727](https://github.com/open-telemetry/opentelemetry-proto/pull/727)
+- all: add missing field comments. [#717](https://github.com/open-telemetry/opentelemetry-proto/pull/717)
+
 ### Removed
 
+- profiles: drop field profile.comment_strindices. [#729](https://github.com/open-telemetry/opentelemetry-proto/pull/729)
 - profiles: remove aggregation temporality enum and field. [#710](https://github.com/open-telemetry/opentelemetry-proto/pull/710)
 
 ## 1.8.0 - 2025-09-02