Ensure rc/stdout/stderr upload when task outputs missing when using AWS Batch

[sberss]

Description

Fixed an issue in the AWS Batch backend where jobs that fail before writing all their expected outputs would cause the delocalization step to fail entirely. This prevented the upload of crucial debugging files (return code, stdout, stderr) to S3.

When a task command fails (e.g., exit 1) before creating all declared outputs, the subsequent delocalization step would attempt to upload these missing files. With set -e enabled, the first failed upload would abort the entire delocalization block, meaning rc/stdout/stderr were never uploaded if they came after a missing output file.

This PR:

1. Removes set -e from the delocalization block - allows all upload attempts to proceed regardless of individual failures.
2. Changes the exit code logic: if the task succeeded (rc=0) but delocalization failed, exit with code 1 (as before). If the task failed (rc≠0) and delocalization also failed, exit with the original task return code. This ensures task failures aren't masked by delocalization failures.

Task rc	Delocalization	Exit code	Rationale
0	Success	0	Everything worked
0	Failed	1	Task succeeded but outputs missing = real problem
≠0	Success	rc	Task failed, outputs captured
≠0	Failed	rc	Task failed, missing outputs expected

Example task to reproduce the issue:

task EarlyFailure {

  command {
    echo "Hello, World" > hello.txt
    exit 1
    echo "Goodbye, World" > goodbye.txt
  }

  output {
    File hello = "hello.txt"
    File goodbye = "goodbye.txt"
  }
}

Prior to this PR, the generated script would attempt to delocalize goodbye.txt to S3, fail as it does not exist and exit before it uploaded the RC, stdout and stderr.

Release Notes Confirmation

CHANGELOG.md

• I updated CHANGELOG.md in this PR
• I assert that this change shouldn't be included in CHANGELOG.md because it doesn't impact community users

Terra Release Notes

• I added a suggested release notes entry in this Jira ticket
• I assert that this change doesn't need Jira release notes because it doesn't impact Terra users

[LizBaldo]

Thank you @sberss
Our team will be reviewing your PRs and approve the necessary steps to get it merged (same with your other Prs)