Only fetch gtest when building tests

CMakeLists.txt

@@ -13,7 +13,7 @@ execute_process(
 )
 FetchContent_Declare(googletest
 	GIT_REPOSITORY https://github.com/google/googletest.git
-	GIT_TAG release-1.11.0
+	GIT_TAG main
 )
 FetchContent_MakeAvailable(googletest)
 
@@ -70,7 +70,20 @@ install(TARGETS ${ISO22133_TARGET}
 # Tests
 
 # Only build tests if we are on x86_64 and not cross compiling
-if ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64" AND ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "${CMAKE_HOST_SYSTEM_PROCESSOR}"))
+if (BUILD_TESTING AND "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64" AND ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "${CMAKE_HOST_SYSTEM_PROCESSOR}"))
+	# Dependencies
+	include(FetchContent)
+	execute_process(
+		COMMAND ping www.github.com -c 1 -q
+		ERROR_QUIET
+		RESULT_VARIABLE NO_CONNECTION
+	)
+	FetchContent_Declare(googletest
+		GIT_REPOSITORY https://github.com/google/googletest.git
+		GIT_TAG release-1.11.0
+	)
+	FetchContent_MakeAvailable(googletest)
+
 	enable_testing()
 	file(GLOB TEST_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/tests/*.cpp)
 	add_executable(${ISO22133_TARGET}_test