compiler: Warn user when immediately converting gradient macro to color #18582

Job	Run time
cpp_cmake (macos-14, 1.77)	9m 15s
cpp_test_driver (ubuntu-22.04)	9m 3s
cpp_cmake (windows-2022, nightly)	9m 33s
build_and_test (ubuntu-22.04, 1.77)	16m 40s
android	4m 2s
cpp_test_driver (macos-13)	8m 13s
cpp_cmake (ubuntu-22.04, stable)	7m 41s
build_and_test (macos-14, stable)	19m 46s
cpp_test_driver (windows-2022)	9m 19s
build_and_test (windows-2022, stable)	23m 47s
build_and_test (windows-2022, 1.77)	23m 48s
esp-idf-quick	9m 23s
ffi_32bit_build	2m 25s
build_and_test (windows-2022, beta, --exclude ffmpeg --exclude gstreamer-player)	22m 51s
fmt_test	1m 54s
build_and_test (ubuntu-22.04, nightly)	15m 55s
mcu_esp	3m 18s
mcu (pico-st7789, thumbv6m-none-eabi)	1m 21s
miri	53s
node_test (ubuntu-22.04)	4m 21s
mcu (pico2-st7789, thumbv8m.main-none-eabihf)	1m 23s
python_test (ubuntu-22.04)	1m 43s
node_test (macos-14)	7m 25s
mcu (stm32h735g, thumbv7em-none-eabihf)	1m 23s
python_test (macos-14)	2m 17s
node_test (windows-2022)	6m 42s
updater_test (0.3.0)	1m 52s
python_test (windows-2022)	2m 6s
vsce_build_test	5m 56s
docs / docs	8m 58s
format_lint_typecheck / format_lint_typecheck	2m 3s
tree-sitter / tree-sitter-tests	20s
wasm / wasm	5m 26s
wasm_demo / wasm_demo	3m 24s
cpp_package_test	2m 11s
wasm / build-slintpad	1m 26s
	4h 18m 3s

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