Add Wolfi/Chainguard dev image compatibility to installer script by ericsmalling · Pull Request #151 · pantsbuild/example-python

Addresses issue pantsbuild/pants#21063

Enhance fetch function to use curl or wget based on availability.
Add detection for sha256sum silent/status flag compatibility (for busybox based distros).

These changes would allow Chainguard / Wolfi "-dev" variant image users to run the installer script un-modified.