www/rustypaste: Update to 0.12.1

Description:

• Remove trailing slash in WWW
• Prefer hardcoded strings

ChangeLog: https://github.com/orhun/rustypaste/blob/v0.12.0/CHANGELOG.md

• Added:
  • Add an endpoint for retrieving a list of files
  • Support multiple auth tokens
  • Add new line character to most prominent messages
• Changed:
  • Bump Shuttle to 0.23.0
  • Bump dependencies
• Fixed:
  • Deploy the Shuttle service when a new tag is created

PR: 273053