Make diff validate return 0 if redirect file does not exist (#1734)

* Make diff validate return 0 if redirect file does not exist

* remove other hashFiles usage

Author: Mpdreamz

.github/workflows/preview-build.yml

@@ -300,7 +300,6 @@ jobs:
       - name: 'Validate redirect rules'
         if: >
           env.MATCH == 'true'
-          && ${{ hashFiles('docs/_redirects.yml', 'docs/redirects.yml') != '' }}
           && github.repository == 'elastic/docs-builder'
           && (
             steps.deployment.outputs.result
@@ -315,7 +314,6 @@ jobs:
       - name: 'Validate redirect rules'
         if: >
           env.MATCH == 'true'
-          && ${{ hashFiles('docs/_redirects.yml', 'docs/redirects.yml') != '' }}
           && (
             github.repository != 'elastic/docs-builder'
             && (

src/tooling/docs-builder/Cli/DiffCommands.cs

@@ -45,6 +45,11 @@ public async Task<int> ValidateRedirects([Argument] string? path = null, Cancel
 		var sourceFile = buildContext.ConfigurationPath;
 		var redirectFileName = sourceFile.Name.StartsWith('_') ? "_redirects.yml" : "redirects.yml";
 		var redirectFileInfo = sourceFile.FileSystem.FileInfo.New(Path.Combine(sourceFile.Directory!.FullName, redirectFileName));
+		if (!redirectFileInfo.Exists)
+		{
+			await collector.StopAsync(ctx);
+			return 0;
+		}
 
 		var redirectFileParser = new RedirectFile(redirectFileInfo, buildContext);
 		var redirects = redirectFileParser.Redirects;