Remove Primitive_option.toUndefined; use valFromOption for optional ffi args #10001

Job	Run time
test-devcontainer	17m 23s
build-compiler (macos-15, 5.3.0, true, darwin-arm64, aarch64-apple-darwin, release)	6m 56s
build-compiler (ubuntu-24.04, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, linux...	5m 38s
build-compiler (ubuntu-24.04-arm, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, t...	5m 47s
build-compiler (ubuntu-24.04, ocaml-variants.5.0.0+options,ocaml-option-static, linux-x64, x86_64...	5m 14s
build-compiler (macos-15-intel, 5.3.0, true, darwin-x64, x86_64-apple-darwin, release)	10m 41s
build-compiler (windows-2025, 5.3.0, true, win32-x64, x86_64-pc-windows-gnu, .exe, release)	11m 45s
pkg-pr-new	1m 2s
api-docs	2m 42s
test-installation-pnpm (windows-2025)	55s
test-installation-pnpm (ubuntu-24.04-arm)	23s
test-installation-pnpm (ubuntu-24.04)	17s
test-integration-rewatch (macos-15-intel)	7m 5s
test-integration-rewatch (ubuntu-24.04-arm)	3m 7s
test-installation-pnpm (macos-15)	23s
test-installation-npm (macos-15-intel)	28s
test-installation-npm (macos-15)	18s
test-integration-rewatch (ubuntu-24.04)	3m 57s
test-integration-rewatch (windows-2025)	7m 13s
test-installation-npm (windows-2025)	1m 21s
test-integration-rewatch (macos-15)	4m 40s
test-installation-npm (ubuntu-24.04)	19s
test-installation-npm (ubuntu-24.04-arm)	17s
test-installation-pnpm (macos-15-intel)	37s
publish	0s
	1h 38m 28s

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