Don't use obsolete X509Certificate2 ctor

Author: akoeplinger

src/Microsoft.DotNet.Build.Tasks.Feed/src/PublishArtifactsInManifest.cs

@@ -352,7 +352,11 @@ internal PublishArtifactsInManifestBase ConstructPublishingV3Task(BuildModel bui
                 SkipSafetyChecks = this.SkipSafetyChecks,
                 AkaMSClientId = this.AkaMSClientId,
                 AkaMSClientCertificate = !string.IsNullOrEmpty(AkaMSClientCertificate) ?
+#if NET9_0_OR_GREATER
+                    X509CertificateLoader.LoadPkcs12(Convert.FromBase64String(File.ReadAllText(AkaMSClientCertificate)), password: null) : null,
+#else
                     new X509Certificate2(Convert.FromBase64String(File.ReadAllText(AkaMSClientCertificate))) : null,
+#endif
                 AkaMSCreatedBy = this.AkaMSCreatedBy,
                 AkaMSGroupOwner = this.AkaMSGroupOwner,
                 AkaMsOwners = this.AkaMsOwners,

src/Microsoft.DotNet.Deployment.Tasks.Links/src/AkaMSLinksBase.cs

@@ -24,7 +24,11 @@ protected AkaMSLinkManager CreateAkaMSLinksManager()
             AkaMSLinkManager manager;
             if (!string.IsNullOrEmpty(ClientCertificate))
             {
+#if NET9_0_OR_GREATER
+                manager = new AkaMSLinkManager(ClientId, X509CertificateLoader.LoadPkcs12(Convert.FromBase64String(File.ReadAllText(ClientCertificate)), password: null), Tenant, Log);
+#else
                 manager = new AkaMSLinkManager(ClientId, new X509Certificate2(Convert.FromBase64String(File.ReadAllText(ClientCertificate))), Tenant, Log);
+#endif
             }
             else if (!string.IsNullOrEmpty(ClientSecret))
             {