[Interop] Update image versions (#36784)

Use 1.63.1 and 1.64.1 for C++. Use 1.64.1 for Python.

Closes #36784

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/36784 from yashykt:UpdateInterop 9a25ffed27
PiperOrigin-RevId: 638919524

tools/interop_matrix/client_matrix.py

@@ -132,8 +132,8 @@ LANG_RELEASE_MATRIX = {
             ("v1.60.0", ReleaseInfo()),
             ("v1.61.0", ReleaseInfo()),
             ("v1.62.0", ReleaseInfo()),
-            ("v1.63.0", ReleaseInfo()),
-            ("v1.64.0", ReleaseInfo()),
+            ("v1.63.1", ReleaseInfo()),
+            ("v1.64.1", ReleaseInfo()),
         ]
     ),
     "go": OrderedDict(
@@ -791,7 +791,7 @@ LANG_RELEASE_MATRIX = {
                 ),
             ),
             (
-                "v1.64.0",
+                "v1.64.1",
                 ReleaseInfo(
                     runtimes=["python"], testcases_file="python__master"
                 ),