editors/encryptpad: Undeprecate and update to 0.5.0.4

Undrepecate by removing expired security/botan2 dependency.
Switch to botan3 branch until not merged into releases.

ChangeLog: https://github.com/evpo/EncryptPad/blob/botan3/CHANGES.md
MFH: 2025Q2

(cherry picked from commit b56744ea9c2b69eb62b45e2dca17edab4e05f6e4)