Add mambaforge to github actions ci

Author: phofl

.github/workflows/database.yml

@@ -88,6 +88,8 @@ jobs:
 
     - uses: conda-incubator/setup-miniconda@v2
       with:
+        mamba-version: "*"
+        channels: conda-forge,defaults
         activate-environment: pandas-dev
         channel-priority: strict
         environment-file: ${{ matrix.ENV_FILE }}

.github/workflows/posix.yml

@@ -81,6 +81,8 @@ jobs:
 
     - uses: conda-incubator/setup-miniconda@v2
       with:
+        mamba-version: "*"
+        channels: conda-forge,defaults
         activate-environment: pandas-dev
         channel-priority: flexible
         environment-file: ${{ env.ENV_FILE }}