Start migration off defaults to conda-forge channel (facebookresearch#4126)

Summary: Pull Request resolved: facebookresearch#4126

Differential Revision: D68043874

Author: Michael Norris

.github/actions/build_cmake/action.yml

@@ -24,16 +24,23 @@ runs:
       with:
         python-version: '3.11'
         miniconda-version: latest
+        channels: conda-forge,nodefaults
+        conda-remove-defaults: "true"
     - name: Configure build environment
       shell: bash
       run: |
         # initialize Conda
+        conda config --show channels
+        conda config --remove channels defaults
+        conda config --show channels
         conda config --set solver libmamba
         conda update -y -q conda
         echo "$CONDA/bin" >> $GITHUB_PATH
+        conda config --show channels
 
         conda install -y -q python=3.11 cmake=3.26 make=4.2 swig=4.0 "numpy<2" scipy=1.14 pytest=7.4 gflags=2.2
 
+        conda config --show channels
         # install base packages for ARM64
         if [ "${{ runner.arch }}" = "ARM64" ]; then
           conda install -y -q -c conda-forge openblas=0.3 gxx_linux-aarch64=14.2 sysroot_linux-aarch64=2.17
@@ -65,6 +72,7 @@ runs:
         else
           conda install -y -q "pytorch<2.5" -c pytorch
         fi
+        conda config --show channels
     - name: ROCm - Install dependencies
       if: inputs.rocm == 'ON'
       shell: bash

.github/actions/build_conda/action.yml

@@ -31,6 +31,8 @@ runs:
       with:
         python-version: '3.11'
         miniconda-version:  latest
+        channels: conda-forge,nodefaults
+        conda-remove-defaults: "true"
     - name: Install conda build tools
       shell: ${{ steps.choose_shell.outputs.shell }}
       run: |