Revert parts of previous commit

Author: ncooke3

FirebaseAuth/Sources/ObjC/FIRRecaptchaBridge.m

@@ -174,16 +174,6 @@
         } catch {
           return ("", error, true, true)
         }
-      } else if let recaptcha = NSClassFromString("Recaptcha") {
-        // Fall back to attempting to connect with pre-18.7.0 RecaptchaEnterprise.
-        do {
-          let recaptcha = __fir_castToRecaptchaProtocolFromClass(recaptcha)
-          let client = try await recaptcha.getClient(withSiteKey: siteKey)
-          recaptchaClient = client
-          return await retrieveToken(actionString: actionString, fakeToken: fakeToken)
-        } catch {
-          return ("", error, true, true)
-        }
       } else {
         // RecaptchaEnterprise not linked.
         return ("", nil, false, false)
@@ -198,12 +188,6 @@
         let action = recaptchaAction.init(customAction: actionString)
         let token = try? await recaptchaClient!.execute(withAction: action)
         return (token ?? "NO_RECAPTCHA", nil, true, true)
-      } else if let recaptchaAction = NSClassFromString("RecaptchaAction") {
-        // Fall back to attempting to connect with pre-18.7.0 RecaptchaEnterprise.
-        let recaptchaAction = __fir_castToRecaptchaActionProtocolFromClass(recaptchaAction)
-        let action = recaptchaAction.init(customAction: actionString)
-        let token = try? await recaptchaClient!.execute(withAction: action)
-        return (token ?? "NO_RECAPTCHA", nil, true, true)
       } else {
         // RecaptchaEnterprise not linked.
         return ("", nil, false, false)