feat: add --boot-disk-size option for AWS Batch Forge CE

[ejseqera]

Add support for --boot-disk-size option in AWS Batch Forge compute environments

Description

Fix for #470, this PR adds support for the --boot-disk-size option when creating AWS Batch Forge compute environments, allowing users to specify a custom EBS boot disk size (in GB) for their EC2 instances.

Changes

• Added --boot-disk-size command-line option to AwsBatchForgePlatform advanced options
• The option sets the ebsBootSize parameter in the ForgeConfig object, which is sent in the POST request to /compute-envs
• Implementation follows the same pattern as the existing Google Batch platform

Usage

tw compute-envs add aws-batch forge \
  -n "my-compute-env" \
  -r "us-east-1" \
  --work-dir "s3://my-bucket/work" \
  --max-cpus 100 \
  --boot-disk-size 100