Fix flakey test by disabling EC2 metadata lookup in test case (#1005)

## Summary
- Disable EC2 IMDS lookups inside
`TestCreateWorkerDeploymentVersion_Errors`.
- Keep the fake AWS Lambda validation failure deterministic and local.

## Root Cause
The test intentionally passes fake AWS Lambda and assume-role inputs.
Server-side worker-deployment validation uses
`go.temporal.io/auto-scaled-workers`, which imports the AWS SDK and
validates the `aws-lambda` compute provider. That path builds default
AWS config and calls STS/Lambda validation.

Before STS can assume the fake role, the AWS SDK needs base credentials.
In a local or CI environment with no AWS env creds/profile/container
creds, the AWS SDK falls back to EC2 Instance Metadata Service. Outside
EC2, that means waiting on IMDS/network retries even though the test
only wants an expected validation failure.

## Scope of the Fix
This is broader AWS SDK behavior: `AWS_EC2_METADATA_DISABLED=true` is
useful for any test/process that invokes AWS SDK default credential
resolution without real credentials and should not hit EC2 IMDS.

In this CLI test suite, the enabled surface is narrow:
- `TestCreateWorkerDeploymentVersion_Errors` is the only enabled test
that passes a complete fake AWS Lambda compute config to the server.
- The later missing-field subcases in that same test fail in CLI-side
validation before server-side AWS validation.
- `TestCreateWorkerDeploymentVersion_LambdaComputeConfig` would also hit
the AWS path, but it is skipped because it needs real AWS fixtures.

So the fix is intentionally test-local rather than package-wide, to
avoid changing behavior for future tests that might intentionally
exercise AWS credential resolution.

## Validation
- `go test -mod=readonly ./internal/temporalcli -run
'TestSharedServerSuite/TestCreateWorkerDeploymentVersion_Errors'
-count=1 -v`

Co-authored-by: Alex Stanfield <13949480+chaptersix@users.noreply.github.com>

Author: kevinawoo

internal/temporalcli/commands.worker.deployment_test.go

@@ -1199,6 +1199,10 @@ func (s *SharedServerSuite) TestCreateWorkerDeploymentVersion_EmptyComputeConfig
 }
 
 func (s *SharedServerSuite) TestCreateWorkerDeploymentVersion_Errors() {
+	// Keep the fake AWS validation case local; otherwise the SDK tries EC2 IMDS
+	// during credential resolution and waits on network retries.
+	s.T().Setenv("AWS_EC2_METADATA_DISABLED", "true")
+
 	deploymentName := uuid.NewString()
 	taskQueue := uuid.NewString()