feat: Raise minimum supported version to 12.1

There is no reason to support the 12.0 version, which is outdated for
many years already. We still support all other minors for v12.

test/spec/Feature/Query/JsonOperatorSpec.hs

@@ -7,13 +7,11 @@ import Test.Hspec
 import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON
 
-import PostgREST.Config.PgVersion (PgVersion, pgVersion121)
-
 import Protolude  hiding (get)
 import SpecHelper
 
-spec :: PgVersion -> SpecWith ((), Application)
-spec actualPgVersion = describe "json and jsonb operators" $ do
+spec :: SpecWith ((), Application)
+spec = describe "json and jsonb operators" $ do
   context "Shaping response with select parameter" $ do
     it "obtains a json subfield one level with casting" $
       get "/complex_items?id=eq.1&select=settings->>foo::json" `shouldRespondWith`
@@ -27,12 +25,8 @@ spec actualPgVersion = describe "json and jsonb operators" $ do
 
     it "fails on bad casting (data of the wrong format)" $
       get "/complex_items?select=settings->foo->>bar::integer"
-        `shouldRespondWith` (
-        if actualPgVersion >= pgVersion121 then
+        `shouldRespondWith`
         [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for type integer: \"baz\""} |]
-        else
-        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
-                            )
         { matchStatus  = 400 , matchHeaders = [] }
 
     it "obtains a json subfield two levels (string)" $