Fixing the following exception in the pipeline. (#3346)

Unhandled exception. System.Exception: sigcheck.exe test failed. Following files are unsigned:
d:\a\_work\1\s\artifacts\postsigntest\azure.functions.cli.min.win-arm64.4.0.5065\_manifest\manifest.json.sha256,
d:\a\_work\1\s\artifacts\postsigntest\azure.functions.cli.min.win-arm64.4.0.5065\_manifest\spdx_2.2\manifest.spdx.json.sha256

Author: khkh-ms

build/Settings.cs

@@ -201,7 +201,7 @@ public class SignInfo
             public static readonly string ToThirdPartySign = "ThirdParty";
             public static readonly string ToMacSign = "Mac";
             public static readonly string[] RuntimesToSign = new string[] { "min.win-arm64", "min.win-x86", "min.win-x64", "osx-arm64", "osx-x64" };
-            public static readonly string[] FilterExtensionsSign = new[] { ".json", ".spec", ".cfg", ".pdb", ".config", ".nupkg", ".py", ".md" };
+            public static readonly string[] FilterExtensionsSign = new[] { ".json", "json.sha256", ".spec", ".cfg", ".pdb", ".config", ".nupkg", ".py", ".md" };
             public static readonly string SigcheckDownloadURL = "https://functionsbay.blob.core.windows.net/public/tools/sigcheck64.exe";
 
             public static readonly string[] SkipSigcheckTest = new[] {