flake.lock: Update

Flake lock file updates:

• Updated input 'hydra':
    'git+https://git.lix.systems/lix-project/hydra.git?ref=refs/heads/main&rev=b0e9b4b2f99f9d8f5c4e780e89f955c394b5ced4' (2024-07-17)
  → 'git+https://git.lix.systems/lix-project/hydra.git?ref=refs/heads/main&rev=9a4a5dd624a1cedc7cdc40687815739b228e5c77' (2024-07-20)

flake.lock

@@ -64,10 +64,10 @@
         "treefmt-nix": "treefmt-nix"
       },
       "locked": {
-        "lastModified": 1721397579,
+        "lastModified": 1721409873,
         "narHash": "sha256-h0njWQRvtkjK0NJ/Kgj76sXBhWwq5HGJm7OMcigmNw4=",
         "ref": "refs/heads/refactor",
-        "rev": "c49e591ae59b5d01d3f5d8e59310244dd5da7446",
+        "rev": "54bba654d4279dfd112345b6470547851feb1457",
         "revCount": 267,
         "type": "git",
         "url": "https://git.lix.systems/lix-project/buildbot-nix.git"
@@ -258,11 +258,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1721210741,
-        "narHash": "sha256-jAFXbe8CA6S25NmAwncidyPgBvLK7a8dcj8AdRGaxUY=",
+        "lastModified": 1721473779,
+        "narHash": "sha256-J8LFEasbW6qr7jrUxd0+SWWqNvU7uYEXzzTHI/MBKWA=",
         "ref": "refs/heads/main",
-        "rev": "b0e9b4b2f99f9d8f5c4e780e89f955c394b5ced4",
-        "revCount": 4181,
+        "rev": "9a4a5dd624a1cedc7cdc40687815739b228e5c77",
+        "revCount": 4185,
         "type": "git",
         "url": "https://git.lix.systems/lix-project/hydra.git"
       },