Redundant "default: yaml" in --help command

[azgabur]

There is redundant "default: yaml" information when --help flag is used.

For all generating commands:

• kuadrantctl generate gatewayapi httproute --help
• kuadrantctl generate kuadrant authpolicy --help
• kuadrantctl generate kuadrant ratelimitpolicy --help

Output:

...
Flags:
  -h, --help                   help for ratelimitpolicy
      --oas string             Path to OpenAPI spec file (in JSON or YAML format), URL, or '-' to read from standard input (required)
  -o, --output-format string   Output format: 'yaml' or 'json'. Default: yaml (default "yaml")
...