release-plz: don't set `CARGO_REGISTRY_TOKEN`, not even to an empty s… #134

Job	Run time
Release-plz dry-run	18s
cargo-deny	21s
Lint	4m 16s
Test (ubuntu-latest, clang++, -Werror)	4m 45s
Test (macOS-latest, g++, -Werror)	4m 19s
Test (ubuntu-latest, g++, -Werror)	3m 45s
Test (windows-latest, /WX, x86_64-pc-windows-msvc)	5m 8s
Test (windows-2022, -Werror, x86_64-pc-windows-gnu)	4m 53s
Test (windows-2022, clang++, -Werror, x86_64-pc-windows-msvc)	3m 54s
Test (macOS-latest, clang++, -Werror)	3m 41s
test_success	2s
	35m 22s

Provide feedback