libpathrs v0.2.2 -- "貴様ら全員刀の錆にしてやるぜ。"

This is a minor release of libpathrs which includes some improvements to
our openat2(2) fallback handling (necessary for runc and adapted from a
similar change to pathrs-lite), as well as minor improvements to "cargo
test" runs -- making the default %check RPM scriptlets work properly out
of the box.

Changed

• Add _test_race feature to allow you to opt-out of the race tests when
  testing with cargo test (which resolves the spurious EAGAIN failures you
  get with naive cargo test and cargo nextest runs, along with making the
  whole test run ~50x faster).

Fixed

• Previously, cargo test runs would fail with errors due to the unique
  execution environment that cargo nextest provides. We have resolved those
  differences and now have smoke tests in our CI to make sure that a naive
  cargo test run will succeed.
• libpathrs will now apply the same openat2 retry logic for any usage of
  openat2 (for scoped lookups), to further improve resiliency on busy
  systems.
• Our logic for deciding whether to use openat2(2) or fallback to an O_PATH
  resolver would cache the result to avoid doing needless test runs of
  openat2(2). However, this causes issues when libpathrs is being used by a
  program that applies new seccomp-bpf filters onto itself -- if the filter
  denies openat2(2) then we would return that error rather than falling back
  to the O_PATH resolver. To resolve this issue, we have introduced more
  flexible fallback mechanisms and no longer cache the result if openat2(2)
  was successful (only if there was an error).

Thanks to the following contributors for making this release possible:

• Aleksa Sarai cyphar@cyphar.com
• Kir Kolyshkin kolyshkin@gmail.com

Signed-off-by: Aleksa Sarai cyphar@cyphar.com