Completely remove AWS Java SDK v1

[stanlk]

AWS Java SDK v1 reached full end of support on December 31st, 2025 we need to remove the old references to AWS Java SDK v1: https://aws.amazon.com/blogs/developer/announcing-end-of-support-for-aws-sdk-for-java-v1-x-on-december-31-2025/

aws-glue-schema-registry/multilang-schema-registry/pom.xml

Lines 69 to 73 in b280404

	<dependency>
	<groupId>com.amazonaws</groupId>
	<artifactId>aws-java-sdk-sts</artifactId>
	<version>${aws.sdk.v1.version}</version>
	</dependency>

Now that the v1 SDK has reached full end-of-life support, we need to remove the old references completely.

[jvdadda]

I've submitted a set of PRs to fully remove AWS SDK v1 references, split by component for easier review:

• [Java] Remove AWS SDK v1 STS dependency from serializer-deserializer #503 — Remove SDK v1 STS dependency from serializer-deserializer
• [Java] Remove AWS SDK v1 STS dependency from multilang-schema-registry #504 — Remove SDK v1 STS dependency from multilang-schema-registry
• [Java] Migrate examples module from AWS SDK v1 Kinesis to v2 #505 — Migrate examples module from SDK v1 Kinesis to v2
• [Java] Migrate integration tests region resolution from SDK v1 to v2 #506 — Migrate integration tests region resolution from SDK v1 to v2
• [Java] Remove AWS SDK v1 version property and dependency management from parent POM #507 — Remove SDK v1 version property and dependency management from parent POM (final cleanup)

Additionally, #508 upgrades the Kinesis Producer Library from 0.x (which depends on SDK v1) to 1.x (which uses SDK v2).

All PRs are independent and can be reviewed/merged individually, except #507 which should go last.

cc @knoxy5467 @swaradgat19 @stvbrad @blacktooth — would appreciate a review on these PRs.