deps: Remove caret on @react-native-async-storage/async-storage.

This takes us to v1.15.5, the current latest. No breaking changes
are announced in the changelog [1], but 1.13.3 does announce this:

> After upgrading to v1.13.3+, remember to:
>
> - remove Pods directory (ios/Pods)
> - clean build directory through Xcode (in menu: Product -> Clean
>   Build Folder)
> - install dependencies again (`pod install`)

This didn't seem obviously necessary, but I did it anyway.

v1.13.4 gets us @react-native-async-storage/async-storagefb0ce97e3,
which we'll need for the RN v0.64 upgrade, zulip#4426.

[1] https://github.com/react-native-async-storage/async-storage/releases

Fixes: zulip#4890

ios/Podfile.lock

@@ -336,7 +336,7 @@ PODS:
     - React-jsi (= 0.63.4)
   - rn-fetch-blob (0.11.2):
     - React-Core
-  - RNCAsyncStorage (1.13.0):
+  - RNCAsyncStorage (1.15.5):
     - React-Core
   - RNCMaskedView (0.1.11):
     - React
@@ -674,7 +674,7 @@ SPEC CHECKSUMS:
   React-RCTVibration: ae4f914cfe8de7d4de95ae1ea6cc8f6315d73d9d
   ReactCommon: 73d79c7039f473b76db6ff7c6b159c478acbbb3b
   rn-fetch-blob: f525a73a78df9ed5d35e67ea65e79d53c15255bc
-  RNCAsyncStorage: a52e45079e7df6cee380be6af676a8441d38c42a
+  RNCAsyncStorage: 56a3355a10b5d660c48c6e37325ac85ebfd09885
   RNCMaskedView: 0e1bc4bfa8365eba5fbbb71e07fbdc0555249489
   RNCPushNotificationIOS: 61a7c72bd1ebad3568025957d001e0f0e7b32191
   RNDeviceInfo: 9b6aba9ffaed69ecb72bd13c7bcb0debf277bc9f

package.json

@@ -25,7 +25,7 @@
   },
   "dependencies": {
     "@expo/react-native-action-sheet": "^3.8.0",
-    "@react-native-async-storage/async-storage": "1.13.0",
+    "@react-native-async-storage/async-storage": "^1.13.0",
     "@react-native-community/cameraroll": "^4.0.4",
     "@react-native-community/masked-view": "^0.1.10",
     "@react-native-community/netinfo": "^5.9.5",

yarn.lock

@@ -2133,10 +2133,10 @@
   dependencies:
     "@octokit/openapi-types" "^8.2.0"
 
-"@react-native-async-storage/async-storage@1.13.0":
-  version "1.13.0"
-  resolved "https://registry.yarnpkg.com/@react-native-async-storage/async-storage/-/async-storage-1.13.0.tgz#7b26b04fd2acf95353e7697927939817e46d3166"
-  integrity sha512-c+pKuUe54sysxnqsfG17kaAcd9xJQyTNYDQhZhYf3Ej5khAQPPM85eN2nc1sj1qEnxDde4mcfi3slrOd/KtoSw==
+"@react-native-async-storage/async-storage@^1.13.0":
+  version "1.15.5"
+  resolved "https://registry.yarnpkg.com/@react-native-async-storage/async-storage/-/async-storage-1.15.5.tgz#0d221a5ef1cd7a6494a42fcaad43136d68379afb"
+  integrity sha512-4AYehLH39B9a8UXCMf3ieOK+G61wGMP72ikx6/XSMA0DUnvx0PgaeaT2Wyt06kTrDTy8edewKnbrbeqwaM50TQ==
   dependencies:
     deep-assign "^3.0.0"