C#: Fix deprecation warnings

Author: hvitved

csharp/extractor/Semmle.Extraction.CSharp.Standalone/AssemblyInfo.cs

@@ -146,7 +146,7 @@ public static AssemblyInfo ReadFromFile(string filename)
                  *  loading the same assembly from different locations.
                  */
                 using var pereader = new System.Reflection.PortableExecutable.PEReader(new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read));
-                using var sha1 = new SHA1CryptoServiceProvider();
+                using var sha1 = SHA1.Create();
                 var metadata = pereader.GetMetadata();
                 unsafe
                 {

csharp/extractor/Semmle.Extraction.CSharp.Standalone/BuildAnalysis.cs

@@ -160,7 +160,7 @@ private static string ComputeTempDirectory(string srcDir)
         {
             var bytes = Encoding.Unicode.GetBytes(srcDir);
 
-            using var sha1 = new SHA1CryptoServiceProvider();
+            using var sha1 = SHA1.Create();
             var sha = sha1.ComputeHash(bytes);
             var sb = new StringBuilder();
             foreach (var b in sha.Take(8))

csharp/extractor/Semmle.Util/FileUtils.cs

@@ -84,7 +84,7 @@ public static void TryDelete(string file)
         public static string ComputeFileHash(string filePath)
         {
             using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
-            using var shaAlg = new SHA256Managed();
+            using var shaAlg = SHA256.Create();
             var sha = shaAlg.ComputeHash(fileStream);
             var hex = new StringBuilder(sha.Length * 2);
             foreach (var b in sha)