[cmake] Delete YUZU_USE_CPM forever (#3615)

This option is really confusing, and has long since outlived its
originally intended purpose.

Goodbye forever!

Closes #3467

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3615
Reviewed-by: DraVee <dravee@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

CMakeLists.txt

@@ -62,7 +62,6 @@ if (YUZU_STATIC_ROOM)
     set(Boost_USE_STATIC_LIBS ON)
     set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
     set(OPENSSL_USE_STATIC_LIBS ON)
-    set(YUZU_USE_CPM ON)
 
     set(zstd_FORCE_BUNDLED ON)
     set(fmt_FORCE_BUNDLED ON)
@@ -126,8 +125,6 @@ if (YUZU_STATIC_BUILD)
 
         set(HTTPLIB_USE_BROTLI_IF_AVAILABLE OFF)
     elseif(APPLE)
-        set(YUZU_USE_CPM ON)
-
         set(YUZU_USE_BUNDLED_FFMPEG ON)
         set(YUZU_USE_BUNDLED_SDL2 ON)
         set(YUZU_USE_BUNDLED_OPENSSL ON)
@@ -189,8 +186,6 @@ if (MSVC OR ANDROID)
     set(EXT_DEFAULT ON)
 endif()
 
-option(YUZU_USE_CPM "Use CPM to fetch system dependencies (fmt, boost, etc) if needed. Externals will still be fetched." ${EXT_DEFAULT})
-
 # ffmpeg
 option(YUZU_USE_BUNDLED_FFMPEG "Download bundled FFmpeg" ${EXT_DEFAULT})
 cmake_dependent_option(YUZU_USE_EXTERNAL_FFMPEG "Build FFmpeg from external source" "${PLATFORM_SUN}" "NOT WIN32 AND NOT ANDROID" OFF)
@@ -369,6 +364,8 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
+find_package(RenderDoc MODULE)
+
 # openssl funniness
 if (YUZU_USE_BUNDLED_OPENSSL)
     set(BUILD_SHARED_LIBS OFF)
@@ -380,15 +377,12 @@ endif()
 
 find_package(OpenSSL 3 REQUIRED)
 
-if (YUZU_USE_CPM)
 message(STATUS "Fetching needed dependencies with CPM")
 
 set(BUILD_SHARED_LIBS OFF)
 set(BUILD_TESTING OFF)
 set(ENABLE_TESTING OFF)
 
-    # TODO(crueter): renderdoc?
-
 # boost
 set(BOOST_INCLUDE_LIBRARIES algorithm icl pool container heap asio headers process filesystem crc variant)
 
@@ -460,28 +454,6 @@ if (YUZU_USE_CPM)
         add_library(Opus::opus ALIAS opus)
     endif()
 endif()
-else()
-    # TODO: we can probably just use CPM for this... right?
-    # Enforce the search mode of non-required packages for better and shorter failure messages
-    find_package(fmt 8 REQUIRED)
-
-    if (NOT YUZU_DISABLE_LLVM)
-        find_package(LLVM MODULE COMPONENTS Demangle)
-    endif()
-
-    find_package(nlohmann_json 3.8 REQUIRED)
-    find_package(lz4 REQUIRED)
-    find_package(RenderDoc MODULE)
-    find_package(stb MODULE)
-
-    find_package(Opus 1.3 MODULE REQUIRED)
-
-    find_package(ZLIB 1.2 REQUIRED)
-    find_package(zstd 1.5 REQUIRED MODULE)
-
-    # wow
-    find_package(Boost 1.57.0 CONFIG REQUIRED OPTIONAL_COMPONENTS headers context system fiber filesystem)
-endif()
 
 if(NOT TARGET Boost::headers)
     AddJsonPackage(boost_headers)