Remove deprecated Nodejs18 support from serverless

[kwiatekus]

Description
Remove support to Nodejs18 serverless runtime

AC

• Users should not be able to create new Nodejs18 functions
• Users do not loose their existing Nodejs18 function - those keep running but cannot be edited unless runtime filed is changed.
• Removed runtime should be part of new release and included in the releasae notes and in the "whats new" announcement for customers

Related
We can do it at 16-10-2024 as it fulfills the deprecation period announced by the notice to customers
Nodejs 18 runtime was deprecated with #747

[kwiatekus]

@Cortey @MichalKalke I tested it the following way:

• I installed operator from latest version (1.5.1) and enabled serverless.
• I created nodejs18 function and waited until its served
• I updated operator's image tag main
• Operator restarted the function controller, which reconciled functions.
• My function entered into Configured: False, which is expected, because of: invalid source.inline.dependencies value: cannot find runtime: nodejs18

NAME   CONFIGURED   BUILT   RUNNING   RUNTIME    VERSION   AGE
test   False        True    True      nodejs18   3         15m

What is unexpected though is that the function controller keeps reconciling it in an infinite loop. Looks like this state is not considered as a final step.. and the reconciliation loop expects to be continued. This is visible when using watch option via kubectl:

k get functions test -w                                                                                                                                                              
NAME   CONFIGURED   BUILT   RUNNING   RUNTIME    VERSION   AGE
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m
test   False        True    True      nodejs18   3         16m

but also in the logs of the controller:

k logs -n kyma-system serverless-ctrl-mngr-95cb5dc4c-8dtxw -f
...
version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:47Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:48Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:49Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:50Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:51Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}
{"level":"INFO","timestamp":"2024-10-24T13:40:52Z","logger":"controllers.function","caller":"serverless/fsm.go:76","message":"reconciliation result","context":{"kind":"Function","name":"test","namespace":"default","version":3,"requeueAfter":1,"requeue":false,"error":null}}

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