Fix TarReader_SparseFileTests reflection breaking under Native AOT by replacing with [UnsafeAccessor]#126854

rzikm merged 2 commits intomaindotnet/runtime:mainfrom

copilot/fix-tarreader-sparsefiletests-reflectiondotnet/runtime:copilot/fix-tarreader-sparsefiletests-reflectionCopy head branch name to clipboard