JSX PPX: add Jsx.element return constraint (#7939) #8710

Job	Run time
build-compiler (ubuntu-24.04, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, linux...	18m 23s
build-compiler (ubuntu-24.04-arm, ocaml-variants.5.3.0+options,ocaml-option-static, true, true, t...	14m 54s
build-compiler (ubuntu-24.04, ocaml-variants.4.14.2+options,ocaml-option-static, linux-x64, x86_6...	20m 49s
build-compiler (macos-15, 5.3.0, true, darwin-arm64, aarch64-apple-darwin)	4m 12s
build-compiler (macos-15-intel, 5.3.0, true, darwin-x64, x86_64-apple-darwin)	7m 14s
build-compiler (windows-2022, 5.3.0, true, win32-x64, x86_64-pc-windows-gnu)	5m 25s
pkg-pr-new	51s
api-docs	2m 40s
test-installation-npm (macos-15)	16s
test-installation-npm (macos-15-intel)	35s
test-installation-npm (windows-2022)	56s
test-installation-pnpm (macos-15-intel)	43s
test-installation-npm (ubuntu-24.04-arm)	19s
test-installation-pnpm (ubuntu-24.04)	12s
test-installation-pnpm (ubuntu-24.04-arm)	27s
test-installation-pnpm (macos-15)	21s
test-installation-npm (ubuntu-24.04)	16s
test-integration-rewatch (macos-15-intel)	3m 8s
test-integration-rewatch (macos-15)	1m 35s
test-integration-rewatch (ubuntu-24.04)	1m 21s
test-integration-rewatch (windows-2022)	2m 49s
test-installation-pnpm (windows-2022)	1m 4s
test-integration-rewatch (ubuntu-24.04-arm)	1m 9s
publish	0s
	1h 29m 39s

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