Tests: Fix RunCMake.CMakePresets example PATH format

Since commit 94c955e5 (Tests: Test the CMakePresets.json example in
the documentation, 2020-10-09, v3.19.0-rc1~8^2) we transform the
documented preset example for testing by replacing the generator.
Extend the transformation with a step to fix `PATH` env var syntax.

Tests/RunCMake/CMakePresets/RunCMakeTest.cmake

@@ -316,6 +316,9 @@ run_cmake_presets(OptionalGeneratorField -G "${RunCMake_GENERATOR}")
 # Test the example from the documentation
 file(READ "${RunCMake_SOURCE_DIR}/../../../Help/manual/presets/example.json" _example)
 string(REPLACE "\"generator\": \"Ninja\"" "\"generator\": \"@RunCMake_GENERATOR@\"" _example "${_example}")
+if(CMAKE_HOST_WIN32)
+  string(REPLACE [["PATH": "$env{HOME}/ninja/bin:$penv{PATH}"]] [["PATH": "$env{HOME}/ninja/bin;$penv{PATH}"]] _example "${_example}")
+endif()
 file(WRITE "${RunCMake_BINARY_DIR}/example.json.in" "${_example}")
 set(CMakePresets_FILE "${RunCMake_BINARY_DIR}/example.json.in")
 run_cmake_presets(DocumentationExample --preset=default)