Merge bitcoin/bitcoin#24130: doc: Update the used Qt version

d67fc78 doc: Update the used Qt version (Hennadii Stepanov)

Pull request description:

  Missed in bitcoin/bitcoin#23489.

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Tree-SHA512: f15d83dca1c7dcdb9bd862358cd0e9a2740d88b8eaa0de8223210c9ce89e7526c6f98908bf26d512ff9271d6d59fda1d0c7ac97fcd7ef4b8b0c06d24b9d62f33

Author: fanquake

doc/dependencies.md

@@ -20,7 +20,7 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | PCRE |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | Python (tests) |  | [3.6](https://www.python.org/downloads) |  |  |  |
 | qrencode | [3.4.4](https://fukuchi.org/works/qrencode) |  | No |  |  |
-| Qt | [5.12.11](https://download.qt.io/official_releases/qt/) | [5.9.5](https://github.com/bitcoin/bitcoin/issues/20104) | No |  |  |
+| Qt | [5.15.2](https://download.qt.io/official_releases/qt/) | [5.9.5](https://github.com/bitcoin/bitcoin/issues/20104) | No |  |  |
 | SQLite | [3.32.1](https://sqlite.org/download.html) | [3.7.17](https://github.com/bitcoin/bitcoin/pull/19077) |  |  |  |
 | XCB |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) (Linux only) |
 | systemtap ([tracing](tracing.md))| [4.5](https://sourceware.org/systemtap/ftp/releases/) |  |  |  | |