CI jobs for 3.18.x

[Claus Ibsen]

Hi

After the 3.18.x LTS release we need to update all our CI jobs by

- removing 3.11.x LTS as its EOL
- adding 3.18.x LTS



-- 
Claus Ibsen
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http://davsclaus.com @davsclaus
Camel in Action 2: https://www.manning.com/ibsen2