Fix clean output directory in generate command, not generateall method (#1071)

Author: Mpdreamz

src/Elastic.Markdown/DocumentationGenerator.cs

@@ -88,10 +88,7 @@ public async Task ResolveDirectoryTree(Cancel ctx)
 	public async Task GenerateAll(Cancel ctx)
 	{
 		var generationState = GetPreviousGenerationState();
-		// always delete output folder on CI
-		if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("GITHUB_ACTIONS")))
-			DocumentationSet.ClearOutputDirectory();
-		else if (!Context.SkipMetadata && (Context.Force || generationState == null))
+		if (!Context.SkipMetadata && (Context.Force || generationState == null))
 			DocumentationSet.ClearOutputDirectory();
 
 		if (CompilationNotNeeded(generationState, out var offendingFiles, out var outputSeenChanges))

src/docs-builder/Cli/Commands.cs

@@ -144,7 +144,12 @@ public async Task<int> Generate(
 
 		if (runningOnCi)
 			await githubActionsService.SetOutputAsync("skip", "false");
+
+		// always delete output folder on CI
 		var set = new DocumentationSet(context, logger);
+		if (runningOnCi)
+			set.ClearOutputDirectory();
+
 
 		if (bool.TryParse(githubActionsService.GetInput("metadata-only"), out var metaValue) && metaValue)
 			metadataOnly ??= metaValue;