hls vscode-extension-schema generates a wrong config type

[jneira]

The command outputs for wingaman hole severity option:

 "haskell.plugin.tactics.config.hole_severity": {
        "type": "string",
        "scope": "resource",
        "enumDescriptions": [
            "error",
            "warning",
            "info",
            "hint",
            "none"
        ],
        "default": null,
        "description": "The severity to use when showing hole diagnostics. These
 are noisy, but some editors don't allow jumping to all severities.",
        "enum": [
            1,
            2,
            3,
            4,
            null
        ]
    },

but its type should be integer instead string, as we can check in the enum values. It produced abug in the vscode extension fixed when we changed the type to integer

//cc @berberman @isovector