Update Ruby versions (#141)

Automatically created pull-request to update Ruby and Rubygems versions.

This is the result of running:

```
nix run .#update
```

See the workflow here:
https://github.com/bobvanderlinden/nixpkgs-ruby/blob/master/.github/workflows/update.yml

rubygems/versions.json

@@ -487,13 +487,17 @@
     "3.5.18": {
       "url": "https://github.com/rubygems/rubygems/archive/refs/tags/v3.5.18.tar.gz",
       "hash": "sha256-ORl7kKW+GZ8nycUUUfXIS5QNsWkurSfoGHfAjPJCdJ8="
+    },
+    "3.5.19": {
+      "url": "https://github.com/rubygems/rubygems/archive/refs/tags/v3.5.19.tar.gz",
+      "hash": "sha256-0J+HQTHLfXpN7XVV4FPJfSNG4zzGCQBBjNWkukBrEzM="
     }
   },
   "aliases": {
     "1": "1.8.30",
     "2": "2.7.6",
-    "3": "3.5.18",
-    "3.5": "3.5.18",
+    "3": "3.5.19",
+    "3.5": "3.5.19",
     "3.4": "3.4.22",
     "3.3": "3.3.27",
     "3.2": "3.2.34",
@@ -504,7 +508,7 @@
     "2.2": "2.2.3",
     "2.0": "2.0.15",
     "1.8": "1.8.30",
-    "3_5": "3.5.18",
+    "3_5": "3.5.19",
     "3_4": "3.4.22",
     "3_3": "3.3.27",
     "3_2": "3.2.34",