Address test issue

Author: cheenamalhotra

src/Microsoft.Data.SqlClient/tests/tools/Microsoft.Data.SqlClient.TestUtilities/Fixtures/CertificateFixtureBase.cs

@@ -50,7 +50,7 @@ protected static X509Certificate2 CreateCertificate(string subjectName, IEnumera
 
             rnd.NextBytes(passwordBytes);
             password = Convert.ToBase64String(passwordBytes);
-#if NET
+#if NET9_0_OR_GREATER
             X500DistinguishedNameBuilder subjectBuilder = new X500DistinguishedNameBuilder();
             SubjectAlternativeNameBuilder sanBuilder = new SubjectAlternativeNameBuilder();
             RSA rsaKey = RSA.Create(2048);

src/Microsoft.Data.SqlClient/tests/tools/Microsoft.Data.SqlClient.TestUtilities/Fixtures/ColumnEncryptionCertificateFixture.cs

@@ -27,8 +27,11 @@ public ColumnEncryptionCertificateFixture()
             using (X509Certificate2 createdCertificate = CreateCertificate(nameof(CertificateWithoutPrivateKey), Array.Empty<string>(), Array.Empty<string>()))
             {
                 // This will strip the private key away from the created certificate
+#if NET9_0_OR_GREATER
                 CertificateWithoutPrivateKey = X509CertificateLoader.LoadCertificate(createdCertificate.Export(X509ContentType.Cert));
-
+#else
+                CertificateWithoutPrivateKey = new X509Certificate2(createdCertificate.Export(X509ContentType.Cert));
+#endif
                 AddToStore(CertificateWithoutPrivateKey, StoreLocation.CurrentUser, StoreName.My);
             }