Merge bitcoin/bitcoin#30655: doc: mention bip94 support

99eeb51 [doc] mention bip94 support (glozow)

Pull request description:

  Followup to #29775, noticed while looking at #30604 and #30647. See [release process](https://github.com/bitcoin/bitcoin/blob/master/doc/release-process.md#before-every-major-and-minor-release).

ACKs for top commit:
  maflcko:
    ACK 99eeb51
  fjahr:
    ACK 99eeb51
  tdb3:
    ACK 99eeb51

Tree-SHA512: 95838d3ace7e5d7b1a2481f2d7bd82902081713e6e89dbf21e0dad16d1cf5295e0c1cfda1f03af72304a5844743d24769f5fa04d4dc9f02f36462ef0ae82a552

Author: glozow

doc/bips.md

@@ -30,6 +30,7 @@ BIPs that are implemented by Bitcoin Core:
 * [`BIP 84`](https://github.com/bitcoin/bips/blob/master/bip-0084.mediawiki): The experimental descriptor wallets introduced in **v0.21.0** by default use the Hierarchical Deterministic Wallet derivation proposed by BIP 84. ([PR #16528](https://github.com/bitcoin/bitcoin/pull/16528))
 * [`BIP 86`](https://github.com/bitcoin/bips/blob/master/bip-0086.mediawiki): Descriptor wallets by default use the Hierarchical Deterministic Wallet derivation proposed by BIP 86 since **v23.0** ([PR #22364](https://github.com/bitcoin/bitcoin/pull/22364)).
 * [`BIP 90`](https://github.com/bitcoin/bips/blob/master/bip-0090.mediawiki): Trigger mechanism for activation of BIPs 34, 65, and 66 has been simplified to block height checks since **v0.14.0** ([PR #8391](https://github.com/bitcoin/bitcoin/pull/8391)).
+* [`BIP 94`](https://github.com/bitcoin/bips/blob/master/bip-0094.mediawiki): Testnet 4 (`-testnet4`) supported as of **v28.0** ([PR #29775](https://github.com/bitcoin/bitcoin/pull/29775)).
 * [`BIP 111`](https://github.com/bitcoin/bips/blob/master/bip-0111.mediawiki): `NODE_BLOOM` service bit added, and enforced for all peer versions as of **v0.13.0** ([PR #6579](https://github.com/bitcoin/bitcoin/pull/6579) and [PR #6641](https://github.com/bitcoin/bitcoin/pull/6641)).
 * [`BIP 112`](https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki): The CHECKSEQUENCEVERIFY opcode has been implemented since **v0.12.1** ([PR #7524](https://github.com/bitcoin/bitcoin/pull/7524)), and has been *buried* since **v0.19.0** ([PR #16060](https://github.com/bitcoin/bitcoin/pull/16060)).
 * [`BIP 113`](https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki): Median time past lock-time calculations have been implemented since **v0.12.1** ([PR #6566](https://github.com/bitcoin/bitcoin/pull/6566)), and has been *buried* since **v0.19.0** ([PR #16060](https://github.com/bitcoin/bitcoin/pull/16060)).