Allow lens 5.2

No code changes were required, just needed to bump the upper bounds.
servant-swagger already allows 5.2. In a normal situation you won't get
lens 5.2 yet, because swagger2 currently disallows lens 5.2:
https://github.com/GetShopTV/swagger2/pull/242
Additionally, servant-multipart needs its constraint lifted as well
which I'll PR to the respective repository.

Tested using

    cabal v2-build all --allow-newer=lens --constraint='lens >= 5.2'

servant-auth/servant-auth-docs/servant-auth-docs.cabal

@@ -39,7 +39,7 @@ library
     , servant-docs >= 0.11.2  && < 0.13
     , servant      >= 0.13    && < 0.20
     , servant-auth == 0.4.*
-    , lens         >= 4.16.1  && <5.2
+    , lens         >= 4.16.1  && <5.3
   exposed-modules:
       Servant.Auth.Docs
   default-language: Haskell2010

servant-auth/servant-auth-server/servant-auth-server.cabal

@@ -42,7 +42,7 @@ library
     , entropy                 >= 0.4.1.3  && < 0.5
     , http-types              >= 0.12.2   && < 0.13
     , jose                    >= 0.7.0.0  && < 0.10
-    , lens                    >= 4.16.1   && < 5.2
+    , lens                    >= 4.16.1   && < 5.3
     , memory                  >= 0.14.16  && < 0.18
     , monad-time              >= 0.3.1.0  && < 0.4
     , mtl                     >= 2.2.2    && < 2.3

servant-auth/servant-auth-swagger/servant-auth-swagger.cabal

@@ -37,7 +37,7 @@ library
     , swagger2        >= 2.2.2   && < 3
     , servant         >= 0.13    && < 0.20
     , servant-auth    == 0.4.*
-    , lens            >= 4.16.1  && < 5.2
+    , lens            >= 4.16.1  && < 5.3
   exposed-modules:
       Servant.Auth.Swagger
   default-language: Haskell2010

servant-auth/servant-auth/servant-auth.cabal

@@ -37,7 +37,7 @@ library
     , containers              >= 0.6      && < 0.7
     , aeson                   >= 1.3.1.1  && < 3
     , jose                    >= 0.7.0.0  && < 0.10
-    , lens                    >= 4.16.1   && < 5.2
+    , lens                    >= 4.16.1   && < 5.3
     , servant                 >= 0.15     && < 0.20
     , text                    >= 1.2.3.0  && < 2.1
     , unordered-containers    >= 0.2.9.0  && < 0.3

servant-docs/servant-docs.cabal

@@ -59,7 +59,7 @@ library
     , hashable             >= 1.2.7.0  && < 1.5
     , http-media           >= 0.7.1.3  && < 0.9
     , http-types           >= 0.12.2   && < 0.13
-    , lens                 >= 4.17     && < 5.2
+    , lens                 >= 4.17     && < 5.3
     , string-conversions   >= 0.4.0.1  && < 0.5
     , universe-base        >= 1.1.1    && < 1.2
     , unordered-containers >= 0.2.9.0  && < 0.3

servant-foreign/servant-foreign.cabal

@@ -52,7 +52,7 @@ library
   -- Here can be exceptions if we really need features from the newer versions.
   build-depends:
       base-compat >= 0.10.5  && < 0.13
-    , lens        >= 4.17    && < 5.2
+    , lens        >= 4.17    && < 5.3
     , http-types  >= 0.12.2  && < 0.13
 
   hs-source-dirs:      src