Anonymous module artifact fetch when encountering status 403 (#6284)

Co-authored-by: Stephane Lapointe <stephane.lap@outlook.com>

src/Bicep.Core/Registry/AzureContainerRegistryManager.cs

@@ -8,6 +8,7 @@
 using Bicep.Core.Registry.Oci;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
@@ -38,11 +39,13 @@ public async Task<OciArtifactResult> PullArtifactAsync(RootConfiguration configu
 
             try
             {
+                Trace.WriteLine($"Authenticated attempt to pull artifact for module {moduleReference.FullyQualifiedReference}.");
                 // Try authenticated client first.
                 (manifest, manifestStream, manifestDigest) = await DownloadManifestAsync(moduleReference, client);
             }
-            catch (RequestFailedException exception) when (exception.Status == 401)
+            catch (RequestFailedException exception) when (exception.Status == 401 || exception.Status == 403)
             {
+                Trace.WriteLine($"Authenticated attempt to pull artifact for module {moduleReference.FullyQualifiedReference} failed, received code {exception.Status}. Fallback to anonymous pull.");
                 // Fall back to anonymous client.
                 client = this.CreateBlobClient(configuration, moduleReference, anonymousAccess: true);
                 (manifest, manifestStream, manifestDigest) = await DownloadManifestAsync(moduleReference, client);