update interop client matrix to add 1.18 for core langs

Author: sanjaypujare

tools/interop_matrix/client_matrix.py

@@ -98,6 +98,7 @@ def __init__(self, patch=[], runtime_subset=[], testcases_file=None):
         ('v1.15.0', ReleaseInfo()),
         ('v1.16.0', ReleaseInfo()),
         ('v1.17.1', ReleaseInfo()),
+        ('v1.18.0', ReleaseInfo()),
     ]),
     'go':
     OrderedDict([
@@ -161,6 +162,7 @@ def __init__(self, patch=[], runtime_subset=[], testcases_file=None):
         ('v1.15.0', ReleaseInfo()),
         ('v1.16.0', ReleaseInfo()),
         ('v1.17.1', ReleaseInfo()),
+        ('v1.18.0', ReleaseInfo()),
     ]),
     'node':
     OrderedDict([
@@ -225,6 +227,7 @@ def __init__(self, patch=[], runtime_subset=[], testcases_file=None):
         ('v1.15.0', ReleaseInfo()),
         ('v1.16.0', ReleaseInfo()),
         ('v1.17.1', ReleaseInfo()),
+        ('v1.18.0', ReleaseInfo()),
     ]),
     'csharp':
     OrderedDict([
@@ -249,6 +252,7 @@ def __init__(self, patch=[], runtime_subset=[], testcases_file=None):
         ('v1.15.0', ReleaseInfo()),
         ('v1.16.0', ReleaseInfo()),
         ('v1.17.1', ReleaseInfo()),
+        ('v1.18.0', ReleaseInfo()),
     ]),
 }