CI: also use gdal nightly in nightly-deps tests (#516)

Author: theroggy

ci/envs/nightly-deps.yml

@@ -1,5 +1,6 @@
-name: test
+name: test-nightly-deps
 channels:
+  - gdal-master
   - conda-forge
 dependencies:
   - libgdal-core
@@ -11,6 +12,4 @@ dependencies:
     - numpy>=2.0.0.dev
     - shapely
     - pandas
-    - pyarrow
-
-
+    - pyarrow