Update Code to 1.90.0 (#6824)

Additionally:

- Update Node to 20.11.1
- Update documentation
- Disable extension signature verification

This works around an issue where the Open VSX is not returning the
expected zip.  Verification is skipped later anyway because
@vscode/vsce-sign is missing in the OSS version.

flake.lock

@@ -5,11 +5,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1681202837,
-        "narHash": "sha256-H+Rh19JDwRtpVPAWp64F+rlEtxUWBAQW28eAi3SRSzg=",
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "cfacdce06f30d2b68473a46042957675eebb3401",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
         "type": "github"
       },
       "original": {
@@ -20,12 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1683594133,
-        "narHash": "sha256-iUhLhEAgOCnexSGDsYT2ouydis09uDoNzM7UC685XGE=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "8d447c5626cfefb9b129d5b30103344377fe09bc",
-        "type": "github"
+        "lastModified": 1716137900,
+        "narHash": "sha256-sowPU+tLQv8GlqtVtsXioTKeaQvlMz/pefcdwg8MvfM=",
+        "path": "/nix/store/r8nhgnkxacbnf4kv8kdi8b6ks3k9b16i-source",
+        "rev": "6c0b7a92c30122196a761b440ac0d46d3d9954f1",
+        "type": "path"
       },
       "original": {
         "id": "nixpkgs",