fixed `rultor` merging script

[Graur]

PR-Codex overview

This PR aims to improve the build process by enabling LC_ALL=C in the merge process to avoid issues with non-ASCII characters. It also removes unnecessary environment variables.

Detailed summary

• Added a todo to enable LC_ALL=C in the merge process
• Removed JAVA_TOOL_OPTIONS and MAVEN_OPTS environment variables from the merge and release processes
• Removed LC_ALL=C from the merge script
• Updated the release script to set the new version and commit it to Git

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[Graur]

@yegor256 I fixed rultor merging script which should allow us to merge pull requests in this repository. Can you please check it and merge it manually? Or we can merge #25 manually if you think it would be better

[yegor256]

@Graur done

[Graur]

@yegor256 Thanks!