Separately pin QT nixpkg version (#244)

* Add missing libraries for video player

* Pin qt6 package version to 6.6.3

Currently, this succesfully launches the program. Pinning qt seperatly
allows the rest of unstable nixpkgs to be updated even after the qt
package version has been bumped. This fixes vim failing to launch in the
nix shell because of a bad gcc version. Bumping the package version to
qt6.7.1 also will require bumping PySide to 6.7.1, otherwise it will
fail to find qt. Qt 6.7.1 nixpkg commit is 47da0aee5616a063015f10ea593688646f2377e4

* fixup: Pin Qtcreator also

QtCreator was still against nixpkgs not the specific qt variant.

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1712473363,
-        "narHash": "sha256-TIScFAVdI2yuybMxxNjC4YZ/j++c64wwuKbpnZnGiyU=",
+        "lastModified": 1717602782,
+        "narHash": "sha256-pL9jeus5QpX5R+9rsp3hhZ+uplVHscNJh8n8VpqscM0=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "e89cf1c932006531f454de7d652163a9a5c86668",
+        "rev": "e8057b67ebf307f01bdcc8fba94d94f75039d1f6",
         "type": "github"
       },
       "original": {
@@ -16,9 +16,26 @@
         "type": "github"
       }
     },
+    "qt6Nixpkgs": {
+      "locked": {
+        "lastModified": 1711460435,
+        "narHash": "sha256-Qb/J9NFk2Qemg7vTl8EDCto6p3Uf/GGORkGhTQJLj9U=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "f862bd46d3020bcfe7195b3dad638329271b0524",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "f862bd46d3020bcfe7195b3dad638329271b0524",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "qt6Nixpkgs": "qt6Nixpkgs"
       }
     }
   },