enable operator support for pg15 and drop support for 9.5 and 9.6 (#2140)

* enable operator support for pg15 and drop support for 9.5 and 9.6
* not offer 15 in UI before spilo-15 is available

charts/postgres-operator/crds/operatorconfigurations.yaml

@@ -167,7 +167,7 @@ spec:
                       type: string
                   minimal_major_version:
                     type: string
-                    default: "9.6"
+                    default: "11"
                   target_major_version:
                     type: string
                     default: "14"

charts/postgres-operator/crds/postgresqls.yaml

@@ -367,13 +367,12 @@ spec:
                   version:
                     type: string
                     enum:
-                      - "9.5"
-                      - "9.6"
                       - "10"
                       - "11"
                       - "12"
                       - "13"
                       - "14"
+                      - "15"
                   parameters:
                     type: object
                     additionalProperties:

charts/postgres-operator/values.yaml

@@ -89,7 +89,7 @@ configMajorVersionUpgrade:
   # - acid
 
   # minimal Postgres major version that will not automatically be upgraded
-  minimal_major_version: "9.6"
+  minimal_major_version: "11"
   # target Postgres major version when upgrading clusters automatically
   target_major_version: "14"