Handle Unsupported Dependency Update tool check (#3)

New functionality added as part of the PR ossf#2125 is not supported for
local repositories. When this code path is hit, it will check if it is
an unsupported error and not fail the Dependency Update tool check.
Fallback to existing behavior for any other type of errors

checks/raw/dependency_update_tool.go

@@ -42,7 +42,12 @@ func DependencyUpdateTool(c clients.RepoClient) (checker.DependencyUpdateToolDat
 
 	commits, err := c.SearchCommits(clients.SearchCommitsOptions{Author: "dependabot[bot]"})
 	if err != nil {
-		return checker.DependencyUpdateToolData{}, fmt.Errorf("%w", err)
+		// Do not fail if client returns an unsupported error
+		if strings.Contains(err.Error(), clients.ErrUnsupportedFeature.Error()) {
+			return checker.DependencyUpdateToolData{Tools: tools}, nil
+		} else {
+			return checker.DependencyUpdateToolData{}, fmt.Errorf("%w", err)
+		}
 	}
 
 	for i := range commits {