Relax required files for docc script detection of the SwiftUsd repo root

Author: maddyadams

scripts/docc/Sources/SwiftUsdDoccUtil/FileSystemUtil.swift

@@ -37,15 +37,13 @@ final public class Driver: Sendable {
 
         // Do a smoke test to make sure we have something that looks like the SwiftUsd repo
         let repoContents = try! FileManager.default.contentsOfDirectory(atPath: result.path(percentEncoded: false))
-        assert(repoContents.contains("docs"),                 "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("openusd-patch.patch"),  "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("Package.swift"),        "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("README.md"),            "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("scripts"),              "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("source"),               "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("swift-package"),        "Error! Could not find SwiftUsd repo URL")
         assert(repoContents.contains("SwiftUsd.docc"),        "Error! Could not find SwiftUsd repo URL")
-        assert(repoContents.contains("SwiftUsd.doccarchive"), "Error! Could not find SwiftUsd repo URL")
 
         return result
     }