Update pipelines to support .NET 8

Author: sergezhigunov

.github/workflows/dotnet.yml

@@ -16,10 +16,10 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 7.0.x
+        dotnet-version: 8.0.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build
       run: dotnet build --no-restore -c Release
     - name: Test
-      run: dotnet test --no-build --verbosity normal -c Release -f net7.0
+      run: dotnet test --no-build --verbosity normal -c Release -f net8.0

OpenGost.sln

@@ -18,6 +18,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		.editorconfig = .editorconfig
 		.gitattributes = .gitattributes
 		.gitignore = .gitignore
+		.mailmap = .mailmap
 		Directory.Build.props = Directory.Build.props
 		global.json = global.json
 		Key.snk = Key.snk
@@ -41,6 +42,13 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "benchmarks", "benchmarks",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "OpenGost.Security.Cryptography.Benchmarks", "benchmarks\OpenGost.Security.Cryptography.Benchmarks\OpenGost.Security.Cryptography.Benchmarks.csproj", "{26E62B0D-A094-4AA9-97E8-12D1677405DB}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = ".github", ".github", "{AE977542-3870-4EAC-BCB5-92D3CD474BE7}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "workflows", "workflows", "{D03C0010-6B5F-4CCC-86E8-DA9A47A35801}"
+	ProjectSection(SolutionItems) = preProject
+		.github\workflows\dotnet.yml = .github\workflows\dotnet.yml
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -67,6 +75,7 @@ Global
 		{9234D532-B975-4C2A-A3A5-C319C4334301} = {8B2273E6-40B9-4CFB-94E0-4523F39043DB}
 		{F3588A93-87FB-4715-B491-85000A60EC54} = {7213FB63-9C9A-44A9-A619-08A285AE7AB5}
 		{26E62B0D-A094-4AA9-97E8-12D1677405DB} = {689567F4-3622-4373-9F4E-32D5C51C56C0}
+		{D03C0010-6B5F-4CCC-86E8-DA9A47A35801} = {AE977542-3870-4EAC-BCB5-92D3CD474BE7}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {1B3B4239-F721-4D41-8E9D-FB712341B7DA}