tcpdump: always depend on pkg-config (#376693)

fixes pkgsCross.armv7l-hf-multiplatform.pkgsStatic.tcpdump

pkgs/by-name/tc/tcpdump/package.nix

···
     patchShebangs tests
   '';
 
-  nativeBuildInputs = lib.optional (stdenv.hostPlatform.isStatic) [ pkg-config ];
+  nativeBuildInputs = [ pkg-config ];
 
   nativeCheckInputs = [ perl ];