build: update tokio to 1.41 and Android NDK to r27

Delta Chat for Android does not support Android 4 anymore,
so there is no reason to keep using unsupported NDK.

r27 is the latest LTS version of Android NDK.

Tested:
- `nix build .#deltachat-rpc-server-arm64-v8a-android`
- `nix build .#deltachat-rpc-server-armv6l-linux`

`nix build .#deltachat-rpc-server-x86_64-android`
and
`nix build .#deltachat-rpc-server-x86-android`
still fail, but we do not build it in CI.

flake.lock

@@ -7,11 +7,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1712088936,
-        "narHash": "sha256-mVjeSWQiR/t4UZ9fUawY9OEPAhY1R3meYG+0oh8DUBs=",
+        "lastModified": 1720988215,
+        "narHash": "sha256-nQ0Zx0vAWJo0IOGNFjCOdIkDSgOpMa//GalR8tbTl3A=",
         "owner": "tadfisher",
         "repo": "android-nixpkgs",
-        "rev": "2d8181caef279f19c4a33dc694723f89ffc195d4",
+        "rev": "5a052c62cdb51b210bc0717177d5bd014cba3df1",
         "type": "github"
       },
       "original": {
@@ -29,11 +29,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1711099426,
-        "narHash": "sha256-HzpgM/wc3aqpnHJJ2oDqPBkNsqWbW0WfWUO8lKu8nGk=",
+        "lastModified": 1717408969,
+        "narHash": "sha256-Q0OEFqe35fZbbRPPRdrjTUUChKVhhWXz3T9ZSKmaoVY=",
         "owner": "numtide",
         "repo": "devshell",
-        "rev": "2d45b54ca4a183f2fdcf4b19c895b64fbf620ee8",
+        "rev": "1ebbe68d57457c8cae98145410b164b5477761f4",
         "type": "github"
       },
       "original": {
@@ -150,11 +150,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1711703276,
-        "narHash": "sha256-iMUFArF0WCatKK6RzfUJknjem0H9m4KgorO/p3Dopkk=",
+        "lastModified": 1720768451,
+        "narHash": "sha256-EYekUHJE2gxeo2pM/zM9Wlqw1Uw2XTJXOSAO79ksc4Y=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d8fe5e6c92d0d190646fb9f1056741a229980089",
+        "rev": "7e7c39ea35c5cdd002cd4588b03a3fb9ece6fad9",
         "type": "github"
       },
       "original": {