Release 1.21.0

What's Changed

• chore: [DevOps] bump com.diffplug.spotless:spotless-maven-plugin from 3.6.0 to 3.7.0 in the test group by @dependabot[bot] in #912
• chore: [DevOps] bump org.sonatype.central:central-publishing-maven-plugin from 0.10.0 to 0.11.0 in the plugins group by @dependabot[bot] in #911
• chore: [DevOps] Fix path to prompt-registry spec by @Jonas-Isr in #914
• chore: [DevOps] bump the test group with 2 updates by @dependabot[bot] in #920
• chore: [Orchestration] Update model list by @Jonas-Isr in #919
• feat: [DevOps] Update prompt-registry specification by @sap-ai-sdk-bot[bot] in #915
• feat: [Orchestration] staging & 0.138 by @CharlesDuboisSAP in #925
• fix: [DevOps] Temporary for NVD, use datafeed instead of API by @CharlesDuboisSAP in #921
• chore: [DevOps] bump the github-actions group with 2 updates by @dependabot[bot] in #923
• chore: [DevOps] Add release environment by @Jonas-Isr in #918
• chore: [DevOps] Spec update definition of done now mentions documentation by @CharlesDuboisSAP in #922
• chore: Clean up release notes by @Jonas-Isr in #926
• chore: [DevOps] Update Cloud SDK to 5.32.0 by @CharlesDuboisSAP in #927

Full Changelog: https://github.com/SAP/ai-sdk-java/commits/rel/1.21.0