chore: release 1.5.91

Author: aws-sdk-kotlin-ci

.changes/afeacad1-0f2c-483d-a755-4df1fd6fd440.json

@@ -1,5 +1,14 @@
 # Changelog
 
+## [1.5.91] - 11/25/2025
+
+### Features
+* (**ec2**) This release adds support to view Network firewall proxy appliances attached to an existing NAT Gateway via DescribeNatGateways API NatGatewayAttachedAppliance structure.
+* (**networkfirewall**) Network Firewall release of the Proxy feature.
+* (**organizations**) Add support for policy operations on the S3_POLICY and BEDROCK_POLICY policy type.
+* (**route53**) Adds support for new route53 feature: accelerated recovery.
+* Validate caller-specified AWS regions in client config (i.e., `region` and `regionProvider`)
+
 ## [1.5.90] - 11/24/2025
 
 ### Features

CHANGELOG.md

@@ -7,7 +7,7 @@ org.gradle.jvmargs=-Xmx10g -XX:MaxMetaspaceSize=2G
 org.gradle.parallel=true
 
 # sdk
-sdkVersion=1.5.91-SNAPSHOT
+sdkVersion=1.5.91
 
 # atomicfu
 kotlinx.atomicfu.enableJvmIrTransformation=true