Add v1.26.0 to interop matrix

tools/interop_matrix/client_matrix.py

@@ -102,6 +102,7 @@ LANG_RELEASE_MATRIX = {
         ('v1.22.1', ReleaseInfo()),
         ('v1.23.0', ReleaseInfo()),
         ('v1.24.0', ReleaseInfo()),
+        ('v1.26.0', ReleaseInfo()),
     ]),
     'go':
     OrderedDict(
@@ -222,6 +223,7 @@ LANG_RELEASE_MATRIX = {
         ('v1.22.1', ReleaseInfo()),
         ('v1.23.0', ReleaseInfo()),
         ('v1.24.0', ReleaseInfo()),
+        ('v1.26.0', ReleaseInfo()),
     ]),
     'node':
     OrderedDict([
@@ -278,6 +280,7 @@ LANG_RELEASE_MATRIX = {
         # TODO: https://github.com/grpc/grpc/issues/18262.
         # If you are not encountering the error in above issue
         # go ahead and upload the docker image for new releases.
+        ('v1.26.0', ReleaseInfo()),
     ]),
     'php':
     OrderedDict([
@@ -306,6 +309,7 @@ LANG_RELEASE_MATRIX = {
         ('v1.22.1', ReleaseInfo()),
         ('v1.23.0', ReleaseInfo()),
         ('v1.24.0', ReleaseInfo()),
+        ('v1.26.0', ReleaseInfo()),
     ]),
     'csharp':
     OrderedDict([
@@ -340,5 +344,6 @@ LANG_RELEASE_MATRIX = {
         ('v1.22.1', ReleaseInfo()),
         ('v1.23.0', ReleaseInfo()),
         ('v1.24.0', ReleaseInfo()),
+        ('v1.26.0', ReleaseInfo()),
     ]),
 }