CI/TSML: Use Python 3.11.8

Author: amotl

.github/workflows/timeseries.yml

@@ -37,7 +37,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ 'ubuntu-latest' ]
-        python-version: [ '3.11' ]
+        python-version: [ '3.11.8' ]
         cratedb-version: [ 'nightly' ]
 
     services: