Add diagnostics to confirm that conda-build is present

I do not understand why conda build is failing. Make sure that conda-build is really installed. 

Also removed deprecated Windows regression stanza and updated comments regarding constructor versions.

Author: briantoby

.github/workflows/g2main-test.yml

@@ -32,22 +32,24 @@ jobs:
           environment-file: install/GSAS2main/conda-minbuild.yml
           miniforge-version: latest
 
-      - name: regress conda or conda-standalone on Windows
-        if: inputs.os == 'windows-latest'
-        shell: bash -l {0}
-        run: |
+      # 5/6/26 removing next stanza  to use the lastest constructor now that 3.15 is out
+      #- name: regress conda or conda-standalone on Windows
+      #  if: inputs.os == 'windows-latest'
+      #  shell: bash -l {0}
+      #  run: |
           # regress conda or conda-standalone on Windows until constructor 3.11.2 is out
           # do this here so it is not buried in the .yml
           #conda install constructor=3.11.2   
           #conda install constructor=3.9
-          # 5/6/26 removing next line to use the lastest constructor now that 3.15 is out
           #conda install conda-standalone=24.9.2 # works with constructor 3.11.1
 
       - name: create gsas2main conda package
         shell: bash -l {0}
         run: |
           conda env list 
           conda activate test
+          conda list
+          conda list conda-build
           cd install
           python GSAS2main/makeBldFiles.py
           if [ "$RUNNER_OS" == "Windows" ]; then