Update Keycloak to 26.5 #1484

Job	Run time
run-tests / build	3m 31s
build-dev-container / build-client	9s
build-dev-container / build-server	16m 27s
run-e2e-tests / e2e	4m 31s
deploy-dev-container / deploy	22s
	25m 0s

Provide feedback