Added clean before building for "make check"

Copied over the cleaning part of OpenRA PR 20726. This is because `make check` only reports issues when doing a fresh build.

Makefile

@@ -182,9 +182,10 @@ ifneq ("$(MOD_SOLUTION_FILES)","")
 	@echo "Compiling in Debug mode..."
 ifeq ($(RUNTIME), mono)
 # Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
-	@$(MSBUILD) -t:build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:Mono=true -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
+	@$(MSBUILD) -t:clean\;build -restore -p:Configuration=Debug -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:Mono=true -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
 else
 # Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
+	@$(DOTNET) clean -c Debug --nologo --verbosity minimal
 	@$(DOTNET) build -c Debug -nologo -warnaserror -p:TargetPlatform=$(TARGETPLATFORM) -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
 endif
 endif

make.ps1

@@ -119,6 +119,7 @@ function Check-Command
 	Write-Host "Compiling $modID in Debug configuration..." -ForegroundColor Cyan
 
 	# Enabling EnforceCodeStyleInBuild and GenerateDocumentationFile as a workaround for some code style rules (in particular IDE0005) being bugged and not reporting warnings/errors otherwise.
+	dotnet clean -c Debug --nologo --verbosity minimal
 	dotnet build -c Debug --nologo -warnaserror -p:TargetPlatform=win-x64 -p:EnforceCodeStyleInBuild=true -p:GenerateDocumentationFile=true
 	if ($lastexitcode -ne 0)
 	{