update-template-debian.sh: support updating Debian image information in template files

```console
$ hack/update-template-debian.sh
update-template-debian.sh: Update the Debian image location in the specified templates

Usage:
  update-template-debian.sh [--backports[=<bool>]] [--daily[=<bool>]] [--timestamped[=<bool>]] [--version <version>] <template.yaml>...

Description:
  This script updates the Debian image location in the specified templates.
  If the image location in the template contains a release date in the URL, the script replaces it with the latest available date.
  If no flags are specified, the script uses the version from the image location basename in the template.

  Image location basename format: debian-<version>[-backports]-genericcloud-<arch>[-daily][-<timestamp>].qcow2

  Published Debian image information is fetched from the following URLs:

    https://cloud.debian.org/images/cloud/<codename>[-backports]/[daily/](latest|<timestamp>)/debian-<version>[-backports]-genericcloud-<arch>[-daily][-<timestamp>].json

  The downloaded JSON file will be cached in the Lima cache directory.

Examples:
  Update the Debian image location in templates/**.yaml:
  $ update-template-debian.sh templates/**.yaml

  Update the Debian image location in ~/.lima/debian/lima.yaml:
  $ update-template-debian.sh ~/.lima/debian/lima.yaml

  Update the Debian image location to debian-13-genericcloud-<arch>.qcow2 in ~/.lima/debian/lima.yaml:
  $ update-template-debian.sh --version trixie ~/.lima/debian/lima.yaml

Flags:
  --backports[=<bool>]    Use the backports image
                          The boolean value can be true, false, 1, or 0
  --daily[=<bool>]        Use the daily image
  --timestamped[=<bool>]  Use the timestamped image
  --version <version>     Use the specified version
                          The version can be a codename, version number, or alias (testing, stable, oldstable)
  -h, --help              Print this help message
```

Signed-off-by: Norio Nomura <[email protected]>

Author: norio-nomura