Opt-out of default `major/minor/patch` labels

I want all my dependencies updates from dependabot to have label "patch". I have added that to my config file.

```yaml
version: 2
updates:
- package-ecosystem: "pip"
directory: "/"
target-branch: "develop"
schedule:
interval: "daily"
labels:
- "chore"
- "patch"

- package-ecosystem: "github-actions"
directory: "/"
target-branch: "develop"
schedule:
interval: "daily"
labels:
- "chore"
- "patch"
```

If a dependency does a major or minor version change then I endup with duplicate labels. I use these labels to set the version of my releases so they must always be patch when coming from dependabot.

Example PR's https://github.com/DontShaveTheYak/cloud-radar/pull/12 https://github.com/DontShaveTheYak/cloud-radar/pull/14

Start with the Dependabot configuration shown in the issue and reproduce the duplicate-label behavior using the linked example pull requests. Trace how labels are assigned for pip and github-actions updates, then identify the existing tests for update labels. Done means configured labels can prevent the default major/minor/patch labels from being added.

Written by the indexing model from the issue text.