Relax restrictive upper bound on lens (#2539)

The nix build is broken due to haskell-updates following lens version 5.2.3 and
dhall-lsp-server having this restrictive upper bound on 5.2.

Author: dalpd

dhall-lsp-server/dhall-lsp-server.cabal

@@ -55,7 +55,7 @@ library
     , lsp                  >= 1.2.0.0  && < 1.5
     , rope-utf16-splay     >= 0.3.1.0  && < 0.5
     , hslogger             >= 1.2.10   && < 1.4
-    , lens                 >= 4.16.1   && < 5.2
+    , lens                 >= 4.16.1   && < 5.3
     -- megaparsec follows SemVer: https://github.com/mrkkrp/megaparsec/issues/469#issuecomment-927918469
     , megaparsec           >= 7.0.2    && < 10
     , mtl                  >= 2.2.2    && < 2.3