Uniq.ScopedUUID warnings break Dependabot scan

Our mix dependabot scan is failing on a repo that has this repo as a transitive dependency.

This is an excerpt of the dependabot logs:
```
| ex_doc | dependency_file_not_resolvable | {
| | | "message": "Failed to parse response from Hex helper: warning: defp scope_for/1 is private, @doc attribute is always discarded for private functions/macros/types\n │\n 4 │ @doc \"\"\"\n │ ~~~~~~~~\n │\n └─ lib/scoped_uuid.ex:4: Uniq.ScopedUUID.scope_for/1\n\n warning: function scope_for/1 is unused\n │\n 156 │ defp scope_for(%{scope: scope}), do: scope\n │ ~\n │\n └─ lib/scoped_uuid.ex:156:8: Uniq.ScopedUUID (module)\n\n warning: function fake_dumper/2 is unused\n │\n 171 │ defp fake_dumper(_type, value), do: value\n │ ~\n │\n └─ lib/scoped_uuid.ex:171:8: Uniq.ScopedUUID (module)\n\n warning: function extract_uuid/2 is unused\n │\n 173 │ defp extract_uuid(scoped_uuid, params) do\n │ ~\n │\n └─ lib/scoped_uuid.ex:173:8: Uniq.ScopedUUID (module)\n\n warning: function add_scope/2 is unused\n │\n 166 │ defp add_scope(uuid, params) do\n │ ~\n
| | | }
| avrogen | dependency_file_not_resolvable | {
| | | "message": "Failed to parse response from Hex helper: warning: defp scope_for/1 is private, @doc attribute is always discarded for private functions/macros/types\n │\n 4 │ @doc \"\"\"\n │ ~~~~~~~~\n │\n └─ lib/scoped_uuid.ex:4: Uniq.ScopedUUID.scope_for/1\n\n warning: function scope_for/1 is unused\n │\n 156 │ defp scope_for(%{scope: scope}), do: scope\n │ ~\n │\n └─ lib/scoped_uuid.ex:156:8: Uniq.ScopedUUID (module)\n\n warning: function fake_dumper/2 is unused\n │\n 171 │ defp fake_dumper(_type, value), do: value\n │ ~\n │\n └─ lib/scoped_uuid.ex:171:8: Uniq.ScopedUUID (module)\n\n warning: function extract_uuid/2 is unused\n │\n 173 │ defp extract_uuid(scoped_uuid, params) do\n │ ~\n │\n └─ lib/scoped_uuid.ex:173:8: Uniq.ScopedUUID (module)\n\n warning: function add_scope/2 is unused\n │\n 166 │ defp add_scope(uuid, params) do\n │ ~\n
| | | }
| igniter | dependency_file_not_resolvable | {
| | | "message": "Failed to parse response from Hex helper: warning: defp scope_for/1 is private, @doc attribute is always discarded for private functions/macros/types\n │\n 4 │ @doc \"\"\"\n │ ~~~~~~~~\n │\n └─ lib/scoped_uuid.ex:4: Uniq.ScopedUUID.scope_for/1\n\n warning: function scope_for/1 is unused\n │\n 156 │ defp scope_for(%{scope: scope}), do: scope\n │ ~\n │\n └─ lib/scoped_uuid.ex:156:8: Uniq.ScopedUUID (module)\n\n warning: function fake_dumper/2 is unused\n │\n 171 │ defp fake_dumper(_type, value), do: value\n │ ~\n │\n └─ lib/scoped_uuid.ex:171:8: Uniq.ScopedUUID (module)\n\n warning: function extract_uuid/2 is unused\n │\n 173 │ defp extract_uuid(scoped_uuid, params) do\n │ ~\n │\n └─ lib/scoped_uuid.ex:173:8: Uniq.ScopedUUID (module)\n\n warning: function add_scope/2 is unused\n │\n 166 │ defp add_scope(uuid, params) do\n │ ~\n
```

Start by reading lib/scoped_uuid.ex, focusing on the warnings reported for scope_for/1, add_scope/2, extract_uuid/2, and fake_dumper/2. Reproduce the dependency scan or the relevant Hex helper behavior, then verify that the warnings no longer cause the dependency file to be reported as unresolvable.

Written by the indexing model from the issue text.