Merge bitcoin/bitcoin#28513: ci: Install Homebrew's pkg-config package

43cd802 ci: Install Homebrew's `pkg-config` package (Hennadii Stepanov)

Pull request description:

  Some versions of macOS images lack the `pkg-config` package.

  For example, https://github.com/bitcoin/bitcoin/actions/runs/6248032071/job/16961797066:
  ```
  Runner Image
    Image: macos-13
    Version: 20230417.1
  ```

  ```
  + ./autogen.sh
  configure.ac:16: error: PKG_PROG_PKG_CONFIG macro not found. Please install pkg-config and re-run autogen.sh
  ```

  This PR makes Homebrew install the `pkg-config` package explicitly.

  Also please refer to [macOS Build Guide](https://github.com/bitcoin/bitcoin/blob/master/doc/build-osx.md).

ACKs for top commit:
  kevkevinpal:
    ACK [43cd802](bitcoin/bitcoin@43cd802)
  MarcoFalke:
    lgtm ACK 43cd802
  RandyMcMillan:
    ACK 43cd802

Tree-SHA512: 2b934b22e5f6748634089e0525b92219484e37b2afc11e9fd4c53faf112b33ca1c8deb5b4aa36939bf5c4807e7599d4aabae6335317ecc5d4a4d562bbd7dbdf2

.github/workflows/ci.yml

@@ -68,7 +68,7 @@ jobs:
         run: clang --version
 
       - name: Install Homebrew packages
-        run: brew install boost libevent qt@5 miniupnpc libnatpmp ccache zeromq qrencode libtool automake gnu-getopt
+        run: brew install automake libtool pkg-config gnu-getopt ccache boost libevent miniupnpc libnatpmp zeromq qt@5 qrencode
 
       - name: Set Ccache directory
         run: echo "CCACHE_DIR=${RUNNER_TEMP}/ccache_dir" >> "$GITHUB_ENV"