tailscale: 1.96.3 -> 1.96.4

Patch release that bumps the upstream Go toolchain to fix segmentation
faults on MIPS and Synology platforms. No application-level code changes.

The Nix package already removes the vendored toolchain (`rm -rf ./tool`
in preBuild), so the practical impact for Nix users is minimal.

pkgs/by-name/ta/tailscale/package.nix

@@ -24,7 +24,7 @@
 
 buildGoModule (finalAttrs: {
   pname = "tailscale";
-  version = "1.96.3";
+  version = "1.96.4";
 
   outputs = [
     "out"
@@ -35,7 +35,7 @@ buildGoModule (finalAttrs: {
     owner = "tailscale";
     repo = "tailscale";
     tag = "v${finalAttrs.version}";
-    hash = "sha256-zEXRhnofNxDslnvT3NiAyVjZM1V9I7i4pXzhsIVEIZo=";
+    hash = "sha256-VnAEfY8W+2QPnQLvVFJA7/XyvSnppSdRvgAOgpmRFGM=";
   };
 
   vendorHash = "sha256-rhuWEEN+CtumVxOw6Dy/IRxWIrZ2x6RJb6ULYwXCQc4=";