all: update Go dependencies

Routine bump of direct Go dependencies. Notable updates:

  * tailscale.com v1.94.1 -> v1.96.5 (gvisor bumped in lockstep to
    match upstream tailscale go.mod)
  * modernc.org/sqlite v1.44.3 -> v1.48.2, modernc.org/libc v1.67.6
    -> v1.70.0 (updated together as required by the fragile libc
    dependency noted in #2188)
  * google.golang.org/grpc v1.78.0 -> v1.80.0
  * grpc-ecosystem/grpc-gateway/v2 v2.27.7 -> v2.28.0
  * tailscale/hujson, tailscale/squibble, tailscale/tailsql
  * golang.org/x/{crypto,net,sync,oauth2,exp,sys,text,time,term,mod,tools}
  * rs/zerolog, samber/lo, sasha-s/go-deadlock, coreos/go-oidc/v3,
    creachadair/command, go-json-experiment/json, pterm/pterm

Update the nix vendorHash to match the new go.sum. Regenerating capver
against tailscale v1.96.5 produces no diff: v1.96.0 was already
captured in 442fcdbd and the capability version has not changed in
the patch series.

All unit tests and `golangci-lint run --new-from-rev=main` are clean.

flake.nix

@@ -27,7 +27,7 @@
         let
           pkgs = nixpkgs.legacyPackages.${prev.stdenv.hostPlatform.system};
           buildGo = pkgs.buildGo126Module;
-          vendorHash = "sha256-jom1279Lx2Knff93rfoEgGeBBk+EjJO7GAkaQYlchgY=";
+          vendorHash = "sha256-G+yhItFhlp2XP/Zd9N4nMQf96YMQLuYd069H+Quewtk=";
         in
         {
           headscale = buildGo {