Fix ZipToDirectory closing the input streams

src/Tgstation.Server.Host/IO/DefaultIOManager.cs

@@ -292,7 +292,15 @@ namespace Tgstation.Server.Host.IO
 				if (zipFile == null)
 					throw new ArgumentNullException(nameof(zipFile));
 
-				using var archive = new ZipArchive(zipFile, ZipArchiveMode.Read);
+#if NET7_0_OR_GREATER
+#warning Check if zip file seeking has been addressesed. See https://github.com/tgstation/tgstation-server/issues/1531
+#endif
+
+				// ZipArchive does a synchronous copy on unseekable streams we want to avoid
+				if (!zipFile.CanSeek)
+					throw new ArgumentException("Stream does not support seeking!", nameof(zipFile));
+
+				using var archive = new ZipArchive(zipFile, ZipArchiveMode.Read, true);
 				archive.ExtractToDirectory(path);
 			},
 			cancellationToken,

src/Tgstation.Server.Host/IO/IIOManager.cs

@@ -198,7 +198,7 @@ namespace Tgstation.Server.Host.IO
 		/// Extract a set of <paramref name="zipFile"/> to a given <paramref name="path"/>.
 		/// </summary>
 		/// <param name="path">The path to unzip to.</param>
-		/// <param name="zipFile">The <see cref="Stream"/> of the <see cref="global::System.IO.Compression.ZipArchive"/>.</param>
+		/// <param name="zipFile">The <see cref="Stream"/> of the <see cref="global::System.IO.Compression.ZipArchive"/>. Must have <see cref="Stream.CanSeek"/> set to <see langword="true"/>. Will be read completely and left open. <see cref="Stream.Position"/> will be indeterminate.</param>
 		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
 		/// <returns>A <see cref="Task"/> representing the running operation.</returns>
 		Task ZipToDirectory(string path, Stream zipFile, CancellationToken cancellationToken);