nix: Add deadnix to postgrest-lint and remove dead nix code

nix/tools/devTools.nix

@@ -5,9 +5,7 @@
 , devCabalOptions
 , entr
 , git
-, gnugrep
 , graphviz
-, haskellPackages
 , hsie
 , nix
 , silver-searcher

nix/tools/style.nix

@@ -2,6 +2,7 @@
 , black
 , buildToolbox
 , checkedShellScript
+, deadnix
 , git
 , hlint
 , hsie
@@ -65,10 +66,12 @@ let
         echo "Linting workflows..."
         ${actionlint}/bin/actionlint
 
+        echo "Scanning nix files for unused code..."
+        ${deadnix}/bin/deadnix
+
         echo "Checking consistency of import aliases in Haskell code..."
         ${hsie} check-aliases main src
 
-
         echo "Linting Haskell files..."
         # --vimgrep fixes a bug in ag: https://github.com/ggreer/the_silver_searcher/issues/753
         ${silver-searcher}/bin/ag -l --vimgrep -g '\.l?hs$' . \

nix/tools/withTools.nix

@@ -1,10 +1,6 @@
-{ bash-completion
-, buildToolbox
-, cabal-install
-, cabalTools
+{ buildToolbox
 , checkedShellScript
 , curl
-, devCabalOptions
 , git
 , lib
 , postgresqlVersions
@@ -276,30 +272,6 @@ let
         log-level="$(PGRST_LOG_LEVEL)"
       '';
 
-  waitForPgrstPid =
-    checkedShellScript
-      {
-        name = "postgrest-wait-for-pgrst-pid";
-        docs = "Wait for PostgREST to be running. Needs to be a separate command for timeout to work below.";
-        args = [
-          "ARG_USE_ENV([PGRST_SERVER_UNIX_SOCKET], [], [Unix socket to check for running PostgREST instance])"
-        ];
-      }
-      ''
-        # ARG_USE_ENV only adds defaults or docs for environment variables
-        # We manually implement a required check here
-        # See also: https://github.com/matejak/argbash/issues/80
-        : "''${PGRST_SERVER_UNIX_SOCKET:?PGRST_SERVER_UNIX_SOCKET is required}"
-
-        until [ -S "$PGRST_SERVER_UNIX_SOCKET" ]
-        do
-          sleep 0.1
-        done
-
-        # return pid of postgrest process
-        lsof -t -c '/^postgrest$/' "$PGRST_SERVER_UNIX_SOCKET"
-      '';
-
   waitForPgrstReady =
     checkedShellScript
       {