Allow ignoring dependency in group where major version is zero

[garryod]

Is there an existing issue for this?

• [X] I have searched the existing issues

Feature description

Often times we make use of dependencies which are still in the 'initial development' stage, section 4 of the semver spec specifies that these should be given a major version of zero (i.e. 0.y.z). As such packages are allowed to break their public API at any point it would be useful to be able to filter these out of groups. E.g.:

- package-ecosystem: caargo
  groups:
    minor:
      update-types:
        - minor
        - patch
      exclude-update-types:
        - initial-development

[OJFord]

IMO this is a bug: 0.1.x -> 0.2.y should be treated as major, not minor.