Revert "Convert build scripts to CMake (#13427)"

This reverts commit 354df17d16.

cmake/targets/BuildLibDeflate.cmake

@@ -1,26 +0,0 @@
-include(Macros)
-
-register_repository(
-  NAME
-    libdeflate
-  REPOSITORY
-    ebiggers/libdeflate
-  COMMIT
-    dc76454a39e7e83b68c3704b6e3784654f8d5ac5
-)
-
-register_cmake_command(
-  TARGET
-    libdeflate
-  TARGETS
-    libdeflate_static
-  ARGS
-    -DLIBDEFLATE_BUILD_STATIC_LIB=ON
-    -DLIBDEFLATE_BUILD_SHARED_LIB=OFF
-    -DLIBDEFLATE_BUILD_GZIP=OFF
-  LIBRARIES
-    deflatestatic WIN32
-    deflate UNIX
-  INCLUDES
-    .
-)