Pin black version in tox.ini to 23.12.1

Change-Id: I18b1fc82d2ee631b0d023a71ffc5d4bbba37756a
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

releasenotes/notes/pin_black_version-8ef527516b41dd9b.yaml

+#######################################################################################
+# Copyright ETSI Contributors and Others.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#######################################################################################
+---
+other:
+  - |
+    This change pins black version to 23.12.1 in tox.ini.
+

tox.ini

@@ -43,7 +43,7 @@ commands =
 
 #######################################################################################
 [testenv:black]
-deps = black
+deps = black==23.12.1
 skip_install = true
 commands =
         black --check --diff NG-RO