test: add env var path coverage #1420

Job	Run time
Tests in Containers (ci-homebrew-container, ubuntu-latest, homebrew/brew, x86_64-unknown-linux-musl)	3m 54s
Tests (macos-14, aarch64-apple-darwin, yes)	11m 24s
Tests in Containers (ci-jupyter-container, ubuntu-latest, mcr.microsoft.com/devcontainers/univers...	4m 43s
Tests (ubuntu-latest, x86_64-unknown-linux-musl, yes)	9m 15s
Builds (windows-latest, aarch64-pc-windows-msvc)	4m 54s
Builds (ubuntu-latest, x86_64-unknown-linux-musl, yes)	2m 15s
Builds (macos-latest, x86_64-apple-darwin, yes)	2m 36s
Builds (macos-14, aarch64-apple-darwin, yes)	2m 6s
Tests (macos-latest, x86_64-apple-darwin, yes)	16m 25s
Tests (windows-latest, x86_64-pc-windows-msvc, yes)	7m 51s
Env Tests (ci-poetry-global, windows-latest, x86_64-pc-windows-msvc)	6m 18s
Builds (windows-latest, x86_64-pc-windows-msvc)	5m 10s
Env Tests (ci-poetry-global, ubuntu-latest, x86_64-unknown-linux-musl)	2m 46s
Env Tests (ci-poetry-project, ubuntu-latest, x86_64-unknown-linux-musl)	2m 57s
Env Tests (ci-poetry-custom, windows-latest, x86_64-pc-windows-msvc)	6m 11s
Env Tests (ci-poetry-project, windows-latest, x86_64-pc-windows-msvc)	5m 56s
Env Tests (ci-poetry-custom, ubuntu-latest, x86_64-unknown-linux-musl)	2m 52s
	1h 37m 33s

Provide feedback