fix(bun): install bunx symlink

[booniepepper]

Closes #1680

[booniepepper]

Oops, should have started with a download of the distribution zip instead of reading docs

The zip files from bun contain only the bun executable, and bunx is very literally an alias for bun x

[booniepepper]

More specifically, if I install with the script at https://bun.sh/install then I get bunx as a symlink to bun. Sounds like the bun binary checks its argv[0] process name to decide behavior, I've done that before too for shebang support, it's a fun trick

[jdx]

it'd be good to add a line to e2e/test_bun for a simple test. You could execute this: bunx oclif --version