fix: logger.warn instead of ISE on transcoding options for non-unary gRPC

[Dogacel]

Motivation:

• Soft-fail on error "Only unary methods can be configured with an HTTP/JSON endpoint" #5828
• When an rpc method has transcoding options, the server won't start up.

Modifications:

• Warn and skip the method instead of preventing server startup.

Result:

• Closes Soft-fail on error "Only unary methods can be configured with an HTTP/JSON endpoint" #5828
• Server can start if a gRPC non-unary rpc is configured to have transcoding options.

[github-actions]

🔍 Build Scan® (commit: b6f276f)

Job name	Status	Build Scan®
build-windows-latest-jdk-21	✅	https://ge.armeria.dev/s/kdkkclo3zxdiw
build-self-hosted-unsafe-jdk-8	✅	https://ge.armeria.dev/s/o3nrvksj5fquu
build-self-hosted-unsafe-jdk-21-snapshot-blockhound	✅	https://ge.armeria.dev/s/63a2aszfneitu
build-self-hosted-unsafe-jdk-17-min-java-17-coverage	✅	https://ge.armeria.dev/s/3nuz6sk5r7jak
build-self-hosted-unsafe-jdk-17-min-java-11	✅	https://ge.armeria.dev/s/6ufyxtmfvugp6
build-self-hosted-unsafe-jdk-17-leak	✅	https://ge.armeria.dev/s/hz5oukihafakw
build-self-hosted-unsafe-jdk-11	✅	https://ge.armeria.dev/s/5v5tdthel7uy6
build-macos-12-jdk-21	✅	https://ge.armeria.dev/s/e7yo7sewhehzk

[Dogacel]

I have verified the tests used to fail before the fix on HttpTranscodingService.java.

In my opinion we shouldn't be so harsh about unsupported features and punish developers.

[jrhee17]

👍 👍 👍

[minwoox]

Thanks, @Dogacel!

[ikhoon]

Thanks, @Dogacel!