Hashing broken symlink fails

[wolfv]

Checks

• [X] I have checked that this issue has not already been reported.

• [X] I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

ln -s bla nonexist
# then have a pixi task that uses `nonexist`
test = {cmd = "echo 'hello'", inputs = ["nonexist"] }

Issue description

Fails with some IO error

Expected behavior

We should not try to resolve broken symlinks and either ignore them or hash where they are pointing to.