Check if fnm is installed before shell setup #2323

Job	Run time
clippy	39s
clippy	44s
Release build for Windows	22s
Release build for Windows	3m 49s
Release build for macOS	1s
Release build for macOS	1m 51s
Build ARM binary (arm64, aarch64-unknown-linux-musl, arm64v8/ubuntu, aarch64)	37s
Build ARM binary (arm64, aarch64-unknown-linux-musl, arm64v8/ubuntu, aarch64)	2m 50s
fmt	18s
fmt	18s
Build static Linux binary	38s
Build static Linux binary	1m 54s
Build ARM binary (arm32, armv7-unknown-linux-gnueabihf, arm32v7/ubuntu, armv7)	37s
Build ARM binary (arm32, armv7-unknown-linux-gnueabihf, arm32v7/ubuntu, armv7)	2m 29s
unit_tests (ubuntu-latest)	38s
unit_tests (ubuntu-latest)	1m 9s
unit_tests (macOS-latest)	1s
unit_tests (macOS-latest)	1m 48s
unit_tests (windows-latest)	21s
unit_tests (windows-latest)	3m 25s
e2e/macos	1s
e2e/macos	2m 58s
e2e/windows	1s
e2e/windows	8m 46s
Ensure command docs are up-to-date	1s
Ensure command docs are up-to-date	31s
e2e/linux	1s
e2e/linux	1m 33s
	38m 21s

Provide feedback