Remove useless CORROSION_NATIVE_TOOLING option

The native tooling was removed, so remove the option.

RELEASES.md

@@ -4,6 +4,8 @@
 
 - The master branch of corrosion now requires CMake 3.22. See also the 
   [v0.4.0 Release notes](#040-lts-2023-06-01) for more details.
+- Removed native tooling and the corresponding option `CORROSION_NATIVE_TOOLING`.
+  Corrosion now always uses pure CMake.
 
 # v0.4.4 (2023-10-06)
 

cmake/Corrosion.cmake

@@ -20,19 +20,9 @@ endif()
 
 option(CORROSION_VERBOSE_OUTPUT "Enables verbose output from Corrosion and Cargo" OFF)
 
-set(CORROSION_NATIVE_TOOLING_DESCRIPTION
-    "Use native tooling - Required on CMake < 3.19 and available as a fallback option for recent versions"
-    )
-
 set(CORROSION_RESPECT_OUTPUT_DIRECTORY_DESCRIPTION
     "Respect the CMake target properties specifying the output directory of a target, such as
-    `RUNTIME_OUTPUT_DIRECTORY`. This requires CMake >= 3.19, otherwise this option is forced off."
-)
-
-option(
-    CORROSION_NATIVE_TOOLING
-    "${CORROSION_NATIVE_TOOLING_DESCRIPTION}"
-    OFF
+    `RUNTIME_OUTPUT_DIRECTORY`."
 )
 
 option(CORROSION_RESPECT_OUTPUT_DIRECTORY
@@ -46,14 +36,6 @@ option(
     OFF
 )
 
-# The native tooling is required on CMAke < 3.19 so we override whatever the user may have set.
-if (CMAKE_VERSION VERSION_LESS 3.19.0)
-    set(CORROSION_NATIVE_TOOLING ON CACHE INTERNAL "${CORROSION_NATIVE_TOOLING_DESCRIPTION}" FORCE)
-    set(CORROSION_RESPECT_OUTPUT_DIRECTORY OFF CACHE INTERNAL
-        "${CORROSION_RESPECT_OUTPUT_DIRECTORY_DESCRIPTION}" FORCE
-    )
-endif()
-
 find_package(Rust REQUIRED)
 
 if(Rust_TOOLCHAIN_IS_RUSTUP_MANAGED)