fix running unit tests multiple times will cause a rare failed

[tommady]

in the current main branch, the unit tests will fail into rare failures by running the unit test multiple times without single-thread testing setting for the cargo or using serial derive,

below are the failures I can capture.

1. bad file descriptor (os error 9) at Process::new(pid.as_raw()) line caused

thread 'container::container::tests::test_get_set_refresh_status' panicked at 'assertion failed: `(left == right)`
  left: `Stopped`,
 right: `Paused`', src/container/container.rs:337:9

Caused by:
    Bad file descriptor (os error 9)
thread 'container::container::tests::test_refresh_load_save_state' panicked at 'assertion failed: `(left == right)`
  left: `1`,
 right: `0`: the test returned a termination value with a non-zero status code (1) which indicates a failure', /rust
c/c8dfcfe046a7680554bf4eb612bad840e7631c4b/library/test/src/lib.rs:194:5

Caused by:
    0: Bad file descriptor (os error 9)
    1: Bad file descriptor (os error 9)
thread 'container::container::tests::test_get_spec' panicked at 'assertion failed: `(left == right)`
  left: `1`,
 right: `0`: the test returned a termination value with a non-zero status code (1) which indicates a failure', /rust
c/c8dfcfe046a7680554bf4eb612bad840e7631c4b/library/test/src/lib.rs:194:5

Caused by:
    Bad file descriptor (os error 9)
thread 'commands::spec_json::tests::test_spec_json' panicked at 'assertion failed: `(left == right)`
  left: `1`,
 right: `0`: the test returned a termination value with a non-zero status code (1) which indicates a failure', /rust
c/c8dfcfe046a7680554bf4eb612bad840e7631c4b/library/test/src/lib.rs:194:5

thread 'container::builder_impl::tests::setup_uid_mapping_should_succeed' panicked at 'unknown message: 49.', src/pr
ocess/message.rs:17:thread '18container::container::tests::test_get_set_refresh_status
' panicked at 'note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
attempt to subtract with overflow', /home/tommady/.cargo/registry/src/github.com-1ecc6299db9ec823/procfs-0.10.1/src/
process/stat.rs:255:28

thread 'thread 'container::container::tests::test_get_set_refresh_statuscontainer::builder_impl::tests::setup_uid_ma
pping_should_succeed' panicked at '' panicked at 'attempt to subtract with overflowunknown message: 49.', ', /home/t
ommady/.cargo/registry/src/github.com-1ecc6299db9ec823/procfs-0.10.1/src/process/stat.rssrc/process/message.rs::2551
7::2818

note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: Failed to write message [2] to the pipe

Caused by:
    Broken pipe (os error 32)
thread 'container::builder_impl::tests::setup_uid_mapping_should_succeed' panicked at 'assertion failed: `(left == r
ight)`
  left: `1`,
 right: `0`: the test returned a termination value with a non-zero status code (1) which indicates a failure', /rust
c/c8dfcfe046a7680554bf4eb612bad840e7631c4b/library/test/src/lib.rs:194:5

by running

./hack/stress_cargo_test.sh

will be very easy to reproduce.

[tommady]

resolving by adding serial derive into those testcases

1. test_spec_json
2. test_refresh_load_save_state
3. test_get_spec
4. test_get_set_refresh_status

please help review 🙇🏻

[utam0k]

LGTM