DX-120970 Fix macOS: restore original cmake order, document Homebrew regression

Newer Homebrew (runner image >=20260525) added a cmake cask with the same
name as the formula and resolves brew "cmake" to the cask instead of the
formula during brew bundle. Use HOMEBREW_BUNDLE_BREW_SKIP to skip cmake
and boost in brew bundle; they continue to be installed with pinned
versions via the local formula tap in the original position below.

Author: akravchukdremio

dev/tasks/java-jars/github.yml

@@ -125,20 +125,10 @@ jobs:
           # llvm@14 because llvm is newer than llvm@14.
           brew uninstall llvm || :
 
-          # Pin cmake and boost to specific versions before brew bundle to avoid
-          # Homebrew treating cmake as a cask on newer runner images.
-          brew uninstall -f boost || true
-          brew uninstall -f cmake || true
-          mkdir -p homebrew-custom/Formula
-          curl -o homebrew-custom/Formula/cmake.rb https://raw.githubusercontent.com/Homebrew/homebrew-core/f68532bfe5cb87474093df8a839c3818c6aa44dd/Formula/c/cmake.rb
-          curl -o homebrew-custom/Formula/boost.rb https://raw.githubusercontent.com/Homebrew/homebrew-core/23f9c56c5075dd56b4471e2c93f89f6400b49ddd/Formula/b/boost.rb
-          brew tap-new local/homebrew-custom
-          cp ./homebrew-custom/Formula/*.rb "$(brew --repo local/homebrew-custom)/Formula/"
-          brew install -v local/homebrew-custom/cmake
-          brew install -v local/homebrew-custom/boost
-          brew pin cmake
-          brew pin boost
-
+          # cmake and boost are skipped here because newer Homebrew (runner image >=20260525)
+          # added a cmake cask with the same name as the formula and now resolves
+          # `brew "cmake"` to the cask instead of the formula. They are installed below
+          # with pinned versions via a local formula tap.
           HOMEBREW_BUNDLE_BREW_SKIP="cmake boost" brew bundle --file=arrow/cpp/Brewfile
           # We want to link aws-sdk-cpp statically but Homebrew's
           # aws-sdk-cpp provides only shared library. If we have
@@ -157,6 +147,18 @@ jobs:
           # used on test  We uninstall Homebrew's Protobuf to ensure using
           # bundled Protobuf.
           brew uninstall protobuf
+          # fix cmake and boost versions
+          brew uninstall -f boost || true
+          brew uninstall -f cmake || true
+          mkdir -p homebrew-custom/Formula
+          curl -o homebrew-custom/Formula/cmake.rb https://raw.githubusercontent.com/Homebrew/homebrew-core/f68532bfe5cb87474093df8a839c3818c6aa44dd/Formula/c/cmake.rb
+          curl -o homebrew-custom/Formula/boost.rb https://raw.githubusercontent.com/Homebrew/homebrew-core/23f9c56c5075dd56b4471e2c93f89f6400b49ddd/Formula/b/boost.rb
+          brew tap-new local/homebrew-custom
+          cp ./homebrew-custom/Formula/*.rb "$(brew --repo local/homebrew-custom)/Formula/"
+          brew install -v local/homebrew-custom/cmake
+          brew install -v local/homebrew-custom/boost
+          brew pin cmake
+          brew pin boost
 
           brew bundle --file=arrow/java/Brewfile
       - name: Build C++ libraries