Add `typeof!` to `Notations.v` (#1775) #777

Job	Run time
install (dev, 4.11.1, Ubuntu, ubuntu-latest)	37m 44s
install (dev, 4.11.1, macOS, macos-latest)	1h 8m 42s
install (dev, 4.11.1, Windows, windows-latest, -async-proofs-j 1, opam-repository-mingw: https://...	1h 35m 13s
install (8.18.0, 4.11.1, Ubuntu, ubuntu-latest)	38m 5s
install (8.18.0, 4.11.1, macOS, macos-latest)	55m 37s
install (8.18.0, 4.11.1, Windows, windows-latest, -async-proofs-j 1, opam-repository-mingw: https...	1h 34m 27s
install (8.17.0, 4.11.1, Ubuntu, ubuntu-latest)	39m 27s
install (8.17.0, 4.11.1, macOS, macos-latest)	1h 2m 20s
install (8.17.0, 4.11.1, Windows, windows-latest, -async-proofs-j 1, opam-repository-mingw: https...	1h 34m 31s
	9h 46m 6s

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