[BugFix] Fix SCP error raised in sky check

[cblmemo]

To reproduce: in an environment that does not have scp credentials, run sky check:

$ sky check
Checking SCP...Traceback (most recent call last):
  File "/home/txia/miniconda3/envs/skyserve/bin/sky", line 8, in <module>
    sys.exit(cli())
  File "/home/txia/miniconda3/envs/skyserve/lib/python3.9/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "/home/txia/miniconda3/envs/skyserve/lib/python3.9/site-packages/click/core.py", line 1078, in main
    rv = self.invoke(ctx)
  File "/home/txia/skypilot/sky/utils/common_utils.py", line 315, in _record
    return f(*args, **kwargs)
  File "/home/txia/skypilot/sky/cli.py", line 1219, in invoke
    return super().invoke(ctx)
  File "/home/txia/miniconda3/envs/skyserve/lib/python3.9/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/txia/miniconda3/envs/skyserve/lib/python3.9/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/txia/miniconda3/envs/skyserve/lib/python3.9/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "/home/txia/skypilot/sky/utils/common_utils.py", line 336, in _record
    return f(*args, **kwargs)
  File "/home/txia/skypilot/sky/cli.py", line 3519, in check
    sky_check.check(verbose=verbose)
  File "/home/txia/skypilot/sky/check.py", line 20, in check
    ok, reason = cloud.check_credentials()
  File "/home/txia/skypilot/sky/clouds/scp.py", line 312, in check_credentials
    scp_utils.SCPClient().list_instances()
  File "/home/txia/skypilot/sky/clouds/utils/scp_utils.py", line 318, in list_instances
    return self._get(url)
  File "/home/txia/skypilot/sky/clouds/utils/scp_utils.py", line 140, in method_with_retries
    return method(self, *args, **kwargs)
  File "/home/txia/skypilot/sky/clouds/utils/scp_utils.py", line 191, in _get
    raise_scp_error(response)
  File "/home/txia/skypilot/sky/clouds/utils/scp_utils.py", line 114, in raise_scp_error
    raise SCPCreationFailError(f'{status_code}: {message}')
sky.clouds.utils.scp_utils.SCPCreationFailError: 404: Access key not found

Tested (run the relevant ones):

• Code formatting: bash format.sh
• Any manual or new tests for this PR (please specify below)
  • sky check
• All smoke tests: pytest tests/test_smoke.py
• Relevant individual smoke tests: pytest tests/test_smoke.py::test_fill_in_the_name
• Backward compatibility tests: bash tests/backward_comaptibility_tests.sh

[concretevitamin]

Inside a docker

# sky -v
skypilot, version 1.0.0.dev20240126

sky check didn't show this issue?

  SCP: disabled
    Reason: Failed to access SCP with credentials. To configure credentials, see: https://cloud.samsungsds.com/openapiguide
    Generate API key and add the following line to ~/.scp/scp_credential:
      access_key = [YOUR API ACCESS KEY]
      secret_key = [YOUR API SECRET KEY]
      project_id = [YOUR PROJECT ID]

[cblmemo]

Inside a docker

# sky -v
skypilot, version 1.0.0.dev20240126

sky check didn't show this issue?

  SCP: disabled
    Reason: Failed to access SCP with credentials. To configure credentials, see: https://cloud.samsungsds.com/openapiguide
    Generate API key and add the following line to ~/.scp/scp_credential:
      access_key = [YOUR API ACCESS KEY]
      secret_key = [YOUR API SECRET KEY]
      project_id = [YOUR PROJECT ID]

I assume it is the result of an invalid credential in ~/.scp/scp_credential, where in the docker the file does not exist. Could you add the following to the file and try again?

access_key = abc
secret_key = def
project_id = PROJECT-ghi