Update environment.yml

Add nodefaults to ignore global default channels and add specific version of pip dependency

Author: MagdaJuarez

environment.yml

@@ -1,6 +1,7 @@
 name: coast
 channels:
   - conda-forge
+  - nodefaults
 dependencies:
   - python==3.10
   - cython==3.1.1
@@ -10,7 +11,7 @@ dependencies:
   - h5py==3.6.0
   - netCDF4==1.5.8
   - zarr==2.18.3
-  - pip
+  - pip==25.1.1
   - pytest==7.1.1
   - pytest-mock==3.7.0
   - numpy==1.26.4