Rewatch: warnings for unsupported/unknown rescript.json fields #8950

Job	Run time
build-compiler (windows-2025, 5.3.0, true, win32-x64, x86_64-pc-windows-gnu, .exe)	10m 49s
build-compiler (macos-15-intel, 5.3.0, true, darwin-x64, x86_64-apple-darwin)	16m 44s
build-compiler (ubuntu-24.04, ocaml-variants.4.14.2+options,ocaml-option-static, linux-x64, x86_6...	4m 34s
build-compiler (ubuntu-24.04-arm, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, t...	5m 26s
build-compiler (ubuntu-24.04, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, linux...	4m 43s
build-compiler (macos-15, 5.3.0, true, darwin-arm64, aarch64-apple-darwin)	6m 4s
pkg-pr-new	1m 2s
api-docs	1m 22s
test-integration-rewatch (ubuntu-24.04)	1m 18s
test-integration-rewatch (windows-2025)	3m 3s
test-integration-rewatch (macos-15)	1m 46s
test-installation-npm (ubuntu-24.04-arm)	26s
test-installation-pnpm (ubuntu-24.04-arm)	19s
test-installation-pnpm (ubuntu-24.04)	13s
test-installation-npm (ubuntu-24.04)	15s
test-installation-pnpm (windows-2025)	37s
test-installation-pnpm (macos-15)	25s
test-installation-npm (macos-15-intel)	38s
test-installation-npm (macos-15)	24s
test-installation-pnpm (macos-15-intel)	38s
test-installation-npm (windows-2025)	52s
test-integration-rewatch (macos-15-intel)	3m 13s
test-integration-rewatch (ubuntu-24.04-arm)	1m 11s
publish	0s
	1h 6m 2s

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