Fix wrong prose for new epoch environment

[WhatisRT]

Description

The environment for NEWEPOCH is empty, but the prose claimed otherwise. Found in #4043.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated. If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages. New section is never added with the code changes. (See RELEASING.md)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[vsubhuman]

Does this also remove the mention that pools should be removed at the end of their retirement epoch?

[lehins]

Thank you.

[vsubhuman]

Does this also remove the mention that pools should be removed at the end of their retirement epoch?

@WhatisRT ?

[WhatisRT]

Ah, sorry, I missed that from the original discussion. Fixed in #4093.