Upgrade release scripts from `save-state` to environment files

see warnings during release build, e.g. https://github.com/open-telemetry/opentelemetry-proto-java/actions/runs/12641336793/job/35223553825

> Warning: The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

