buildGoPackage: remove Go deps file libs.json

After #16017 there were a lot
of comments saying that `nix` would be better than `JSON`
for Go packages dependency sets.
As said in https://github.com/NixOS/nixpkgs/pull/16017#issuecomment-229624046

    > Because of the content-addressable store, if two programs have the
    > same dependency it will already result in the same derivation in
    > the
    > store. Git also has compression in the pack files so it won't make
    > much difference to duplicate the dependencies on disk. And finally
    > most users will just use the binary builds so it won't make any
    > differences to them.

This PR removes `libs.json` file and puts all package dependencies in
theirs `deps.json`.

pkgs/development/web/minify/deps.json

@@ -1,15 +1,74 @@
 [
     {
-        "include": "../../libs.json",
-        "packages": [
-            "github.com/tdewolff/buffer",
-            "github.com/tdewolff/parse",
-            "github.com/tdewolff/strconv",
-            "github.com/dustin/go-humanize",
-            "github.com/fsnotify/fsnotify",
-            "github.com/matryer/try",
-            "github.com/ogier/pflag",
-            "golang.org/x/sys"
-        ]
+        "goPackagePath": "golang.org/x/sys",
+        "fetch": {
+            "type": "git",
+            "url": "https://go.googlesource.com/sys",
+            "rev": "d9157a9621b69ad1d8d77a1933590c416593f24f",
+            "sha256": "1asdbp7rj1j1m1aar1a022wpcwbml6zih6cpbxaw7b2m8v8is931"
+        }
+    },
+    {
+        "goPackagePath": "github.com/dustin/go-humanize",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/dustin/go-humanize",
+            "rev": "8929fe90cee4b2cb9deb468b51fb34eba64d1bf0",
+            "sha256": "1g155kxjh6hd3ibx41nbpj6f7h5bh54zgl9dr53xzg2xlxljgjy0"
+        }
+    },
+    {
+        "goPackagePath": "github.com/tdewolff/buffer",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/tdewolff/buffer",
+            "rev": "0edfcb7b750146ff879e95831de2ef53605a5cb5",
+            "sha256": "1mdd4k9byp22mw0a399j3w73zjb5g0vn58g76rjy7ajb0dzm80vl"
+        }
+    },
+    {
+        "goPackagePath": "github.com/tdewolff/parse",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/tdewolff/parse",
+            "rev": "34d5c1160d4503da4b456e5094609f2331d6dde3",
+            "sha256": "0hxf65fgkrc1q4p99p33xxxy1s6wxpn1vfsnqf9p846awwbqsy0v"
+        }
+    },
+    {
+        "goPackagePath": "github.com/tdewolff/strconv",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/tdewolff/strconv",
+            "rev": "3e8091f4417ebaaa3910da63a45ea394ebbfb0e3",
+            "sha256": "00w2mryfjhz3vaqzxvbwvyhi1vgpc1s4xfv1r9hxn8hwa078q5gp"
+        }
+    },
+    {
+        "goPackagePath": "github.com/matryer/try",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/matryer/try",
+            "rev": "93d30e50512f879b73829eb79867df38084bcd31",
+            "sha256": "0dmc8iar9685ks1ba3vnycjsx8qxwyqv51jb7677dvwnzbqhgw6f"
+        }
+    },
+    {
+        "goPackagePath": "github.com/fsnotify/fsnotify",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/fsnotify/fsnotify",
+            "rev": "30411dbcefb7a1da7e84f75530ad3abe4011b4f8",
+            "sha256": "0kbpvyi6p9942k0vmcw5z13mja47f7hq7nqd332pn2zydss6kddm"
+        }
+    },
+    {
+        "goPackagePath": "github.com/ogier/pflag",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/ogier/pflag",
+            "rev": "45c278ab3607870051a2ea9040bb85fcb8557481",
+            "sha256": "0620v75wppfd84d95n312wpngcb73cph4q3ivs1h0waljfnsrd5l"
+        }
     }
 ]