Merge bitcoin/bitcoin#23464: doc: remove mention of system univalue from build-unix.md

78e3670 doc: remove mention of system univalue (fanquake)

Pull request description:

  Should have been part of #22646.

ACKs for top commit:
  hebasto:
    ACK 78e3670

Tree-SHA512: a5d54d73526033825ce4467cc3c57c26064739eef546556975a4c6f1f5bea84004640acd426734f90f98bc7a76ec837d716aa31167f2bdce7ee3887ad92e3152

Author: fanquake

doc/build-unix.md

@@ -45,7 +45,6 @@ Optional dependencies:
  libdb4.8    | Berkeley DB      | Optional, wallet storage (only needed when legacy wallet enabled)
  qt          | GUI              | GUI toolkit (only needed when GUI enabled)
  libqrencode | QR codes in GUI  | Optional for generating QR codes (only needed when GUI enabled)
- univalue    | Utility          | JSON parsing and encoding (bundled version will be used unless --with-system-univalue passed to configure)
  libzmq3     | ZMQ notification | Optional, allows generating ZMQ notifications (requires ZMQ version >= 4.0.0)
  sqlite3     | SQLite DB        | Optional, wallet storage (only needed when descriptor wallet enabled)
  systemtap   | Tracing (USDT)   | Optional, statically defined tracepoints