tests: remove unused qualifiers

lib/datasource/readme.md

@@ -9,7 +9,6 @@ The minimum exported interface for a datasource is a function called `getPkgRele
 The `purl` object contains:
 
 - `lookupName`: the package's full name including scope if present (e.g. `@foo/bar`)
-- `qualifiers`: optional addition arguments, may contain fields like `registry`
 
 In the simplest case, the datasource only needs to pay attention to `purl.lookupName`.
 

test/datasource/docker.spec.js

@@ -231,7 +231,6 @@ describe('api/docker', () => {
       got.mockReturnValueOnce({});
       const res = await docker.getPkgReleases({
         lookupName: 'my/node',
-        qualifiers: {},
       });
       expect(res).toBe(null);
     });