[enhancement]: disk_setup support for gpt partitions when sgdisk util is not present

[blackboxsw]

Enhancement

Allow disk_setup of gpt partitions in minimal images where sgdisk utility is not present. Fallback to sfdisk if necessary for handling GPT partition inspection and creation.

Steps to reproduce

1. Launch an ubuntu cloud image, with sgdisk removed , providing disk_setup: in cloud-config which defines a gpt partition table type
2. Expect tracebacks on inability to find sgdisk file or directory

test procedure

1. apply the following diff to tip of main

   diff --git a/tests/integration_tests/conftest.py b/tests/integration_tests/conftest.py
   index b62dae82a..de922735d 100644
   --- a/tests/integration_tests/conftest.py
   +++ b/tests/integration_tests/conftest.py
   @@ -136,6 +136,7 @@ def setup_image(session_cloud: IntegrationCloud, request):
    if source.installs_new_version():
        log.info("Installing cloud-init from %s", source.name)
        client.install_new_cloud_init(source)
   +    client.execute("rm /usr/sbin/sgdisk")
    if (
        integration_settings.INCLUDE_PROFILE
        and integration_settings.INCLUDE_COVERAGE
   diff --git a/tests/integration_tests/modules/test_disk_setup.py b/tests/integration_tests/modules/test_disk_setup.py
   index 27a70d32f..8f8f8b3ec 100644
   --- a/tests/integration_tests/modules/test_disk_setup.py
   +++ b/tests/integration_tests/modules/test_disk_setup.py
   @@ -36,7 +36,7 @@ device_aliases:
   my_alias: /dev/sdb
   disk_setup:
   my_alias:
   -    table_type: mbr
   +    table_type: gpt
    layout: [50, 50]
    overwrite: True
   fs_setup:

2. run integration test, keeping the instance around after test completion

   CLOUD_INIT_KEEP_INSTANCE=1 CLOUD_INIT_PLATFORM=lxd_vm CLOUD_INIT_CLOUD_INIT_SOURCE=ppa:cloud-init-dev/daily CLOUD_INIT_OS_IMAGE=jammy tox -e integration-tests -- tests/integration_tests/modules/test_disk_setup.py::TestDeviceAliases

3. See warnings about disk setup failing due to missing utilities:

   root@cloudinit-1008-135436hv703bwv:~# cloud-init status --format=yaml
   ---
   _schema_version: '1'
   boot_status_code: enabled-by-generator
   datasource: lxd
   detail: DataSourceLXD
   errors: []
   extended_status: degraded done
   init:
   errors: []
   finished: 3.98
   recoverable_errors:
       WARNING:
       - 'Failed partitioning operation
   
           Error running partition command on /dev/sdb
   
           Unexpected error while running command.
   
           Command: [''sgdisk'', ''-p'', ''/dev/sdb'']
   
           Exit code: -
   
           Reason: [Errno 2] No such file or directory: b''sgdisk''
   
           Stdout: -
   
           Stderr: -'
       - Path %s does not exist or is not a block device
       - Path %s does not exist or is not a block device
   start: 3.31
   init-local:
   errors: []
   finished: 2.05
   recoverable_errors: {}
   start: 1.94
   last_update: Thu, 01 Jan 1970 00:00:06 +0000
   modules-config:
   errors: []
   finished: 5.8
   recoverable_errors: {}
   start: 5.55
   modules-final:
   errors: []
   finished: 6.04
   recoverable_errors: {}
   start: 5.97
   recoverable_errors:
   WARNING:
   - 'Failed partitioning operation
   
       Error running partition command on /dev/sdb
   
       Unexpected error while running command.
   
       Command: [''sgdisk'', ''-p'', ''/dev/sdb'']
   
       Exit code: -
   
       Reason: [Errno 2] No such file or directory: b''sgdisk''
   
       Stdout: -
   
       Stderr: -'
   - Path %s does not exist or is not a block device
   - Path %s does not exist or is not a block device