deps: Update pixi tool constraint to >=0.68.0 (#751)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

renovate.json

@@ -6,7 +6,7 @@
   "labels": ["dependencies"],
   "rangeStrategy": "bump",
   "constraints": {
-    "pixi": ">=0.67.2"
+    "pixi": ">=0.68.0"
   },
   "minimumReleaseAge": "14 days",
   "packageRules": [{