Merge fort-nix/nix-bitcoin#847: update nixpkgs

f51460749a ci: disable the nixos-search test (Jonas Nick)
3b798f5ebf test: increase VM memory to 4 GiB (Jonas Nick)
17f0d98c22 update nixpkgs (Jonas Nick)

Pull request description:

Top commit has no ACKs.

Tree-SHA512: 0e40353d9d7937dd7a80c05416360c30ada7ee231d6263883072d60a707443e765d35f6a393e718ed1ef66f2e2cdbd1deadd6cd720dccb5c5e18711159cda38a

modules/btcpayserver.nix

@@ -239,6 +239,11 @@ in {
             --datadir='${cfg.btcpayserver.dataDir}'
         '';
         User = cfg.btcpayserver.user;
+        # Since 2.4.0, btcpayserver uses `Host.CreateDefaultBuilder`, which sets the
+        # ASP.NET content root to the working directory instead of the app directory.
+        # The web root (`wwwroot`) is resolved relative to the content root, so
+        # btcpayserver must be started from its app directory.
+        WorkingDirectory = "${cfg.btcpayserver.package}/lib/btcpayserver";
         # Also restart after the program has exited successfully.
         # This is required to support restarting from the web interface after
         # interactive plugin installation.