build: Update external download URLs and copyright

- In `CMakeModules/DownloadExternals.cmake`:
    - The `package_base_url` for bundled externals is changed from `citron-emu` to `yuzu-mirror`.
- In `CMakeLists.txt`:
    - The `NASM_DOWNLOAD_URL` is updated to `yuzu-mirror`.
    - The download URL for the compatibility list is changed from `api.citron-emu.org` to `api.yuzu-citron-emu.org`.
    - The download URL for `clang-format` on Windows is updated to `yuzu-mirror`.
- Copyright years and project names are updated in both files.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

CMakeModules/DownloadExternals.cmake

@@ -1,4 +1,5 @@
 # SPDX-FileCopyrightText: 2017 yuzu Emulator Project
+# SPDX-FileCopyrightText: 2025 citron Emulator Project
 # SPDX-License-Identifier: GPL-2.0-or-later
 
 # This function downloads a binary library package from our external repo.
@@ -7,7 +8,7 @@
 #   prefix_var: name of a variable which will be set with the path to the extracted contents
 function(download_bundled_external remote_path lib_name prefix_var)
 
-set(package_base_url "https://github.com/citron-emu/")
+set(package_base_url "https://github.com/yuzu-mirror/")
 set(package_repo "no_platform")
 set(package_extension "no_platform")
 if (WIN32)
@@ -16,7 +17,7 @@ if (WIN32)
 elseif (${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
     set(package_repo "ext-linux-bin/raw/main/")
     set(package_extension ".tar.xz")
-elseif (ANDROID)    
+elseif (ANDROID)
     set(package_repo "ext-android-bin/raw/main/")
     set(package_extension ".tar.xz")
 else()