[build] Remove glfw submodule

We use it from the system.

.gitmodules

@@ -31,9 +31,6 @@
 [submodule "vendor/benchmark"]
 	path = vendor/benchmark
 	url = https://github.com/google/benchmark.git
-[submodule "vendor/glfw"]
-	path = vendor/glfw
-	url = https://github.com/glfw/glfw.git
 [submodule "vendor/eternal"]
 	path = vendor/eternal
 	url = https://github.com/mapbox/eternal.git

vendor/glfw.cmake

@@ -1,30 +0,0 @@
-set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "Build the GLFW example programs" FORCE)
-set(GLFW_BUILD_TESTS OFF CACHE BOOL "Build the GLFW test programs" FORCE)
-set(GLFW_BUILD_DOCS OFF CACHE BOOL "Build the GLFW documentation" FORCE)
-set(GLFW_INSTALL OFF CACHE BOOL "Generate installation target" FORCE)
-
-unset(CMAKE_C_VISIBILITY_PRESET)
-add_subdirectory(vendor/glfw)
-set(CMAKE_C_VISIBILITY_PRESET hidden)
-
-target_compile_options(
-    glfw
-    PRIVATE
-        -Wno-shadow
-        -Wno-unused-parameter
-        -Wno-sign-compare
-        -Wno-missing-field-initializers
-)
-
-if(APPLE)
-    # Don't show OpenGL deprecation warnings.
-    target_compile_options(glfw PRIVATE -Wno-deprecated-declarations -Wno-unguarded-availability-new)
-
-    # get_target_property(DEPLOYMENT_TARGET_VERSION glfw MACOSX_DEPLOYMENT_TARGET) message(STATUS "target: ${DEPLOYMENT_TARGET_VERSION}")
-    set_target_properties(glfw PROPERTIES OSX_DEPLOYMENT_TARGET 10.11)
-endif()
-
-if(CMAKE_GENERATOR STREQUAL "Xcode")
-    # The Xcode generator always tries to link from this directory instead of the actual output dir.
-    set_target_properties(glfw PROPERTIES ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/$<CONFIG>")
-endif()