Add environment file to GitHub workflows

.github/workflows/build-sphinx.yml

@@ -36,11 +36,12 @@ jobs:
       pull-requests: write
 
     env:
-      python-ver: '3.12'
-      CHANNELS: '-c dppy/label/dev -c intel -c conda-forge --override-channels'
-      NO_INTEL_CHANNELS: '-c dppy/label/dev -c conda-forge --override-channels'
-      # Install the latest oneAPI compiler to work around an issue
-      INSTALL_ONE_API: 'yes'
+      environment-file: 'environments/environment.yml'
+      build-with-oneapi-env: 'environments/build_with_oneapi.yml'
+      building-docs-env: 'environments/building_docs.yml'
+      oneapi-pkgs-env: ''
+      # Enable env when it's required to use only conda packages without OneAPI installation
+      # oneapi-pkgs-env: '${{ github.workspace }}/environments/oneapi_pkgs.yml'
 
     steps:
       - name: Cancel Previous Runs
@@ -60,6 +61,7 @@ jobs:
           docker-images: false
 
       - name: Add Intel repository
+        if: env.oneapi-pkgs-env == ''
         run: |
           wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
           cat GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB | gpg --dearmor | sudo tee /usr/share/keyrings/oneapi-archive-keyring.gpg > /dev/null
@@ -75,6 +77,7 @@ jobs:
           sudo apt install --reinstall -y gcc-9 g++-9 libstdc++-9-dev
 
       - name: Install Intel OneAPI
+        if: env.oneapi-pkgs-env == ''
         run: |
           sudo apt install hwloc                           \
                            intel-oneapi-mkl                \
@@ -101,16 +104,25 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Install conda-merge tool
+        uses: BSFishy/pip-action@8f2d471d809dc20b6ada98c91910b6ae6243f318 # v1
+        with:
+          packages: conda-merge
+
+      - name: Merge conda env files
+        run: |
+          conda-merge ${{ env.build-with-oneapi-env }} ${{ env.building-docs-env }} ${{ env.oneapi-pkgs-env }} > ${{ env.environment-file }}
+          cat ${{ env.environment-file }}
+
       - name: Setup miniconda
         id: setup_miniconda
         continue-on-error: true
         uses: conda-incubator/setup-miniconda@505e6394dae86d6a5c7fbb6e3fb8938e3e863830 # v3.1.1
         with:
           miniforge-version: latest
           use-mamba: 'true'
-          channels: conda-forge
           conda-remove-defaults: 'true'
-          python-version: ${{ env.python-ver }}
+          environment-file: ${{ env.environment-file }}
           activate-environment: 'docs'
 
       - name: ReSetup miniconda
@@ -119,35 +131,10 @@ jobs:
         with:
           miniforge-version: latest
           use-mamba: 'true'
-          channels: conda-forge
           conda-remove-defaults: 'true'
-          python-version: ${{ env.python-ver }}
+          environment-file: ${{ env.environment-file }}
           activate-environment: 'docs'
 
-      # Sometimes `mamba install ...` fails due to slow download speed rate, so disable the check in mamba
-      - name: Disable speed limit check in mamba
-        run: echo "MAMBA_NO_LOW_SPEED_LIMIT=1" >> $GITHUB_ENV
-
-      - name: Install sphinx dependencies
-        run: |
-          mamba install sphinx sphinx_rtd_theme
-          pip install sphinxcontrib-googleanalytics==0.4 \
-            pyenchant sphinxcontrib-spelling
-
-      - name: Install dpnp dependencies
-        if: env.INSTALL_ONE_API == 'yes'
-        run: |
-          mamba install numpy dpctl">=0.18.0dev0" cmake cython pytest ninja scikit-build ${{ env.NO_INTEL_CHANNELS }}
-
-      - name: Install dpnp dependencies
-        if: env.INSTALL_ONE_API != 'yes'
-        run: |
-          mamba install numpy dpctl">=0.18.0dev0" mkl-devel-dpcpp onedpl-devel tbb-devel dpcpp_linux-64 \
-              cmake cython pytest ninja scikit-build ${{ env.CHANNELS }}
-
-      - name: Install cuPy dependencies
-        run: mamba install cupy
-
       - name: Conda info
         run: mamba info
 
@@ -178,7 +165,6 @@ jobs:
           echo PROJECT_NUMBER=${PROJECT_NUMBER}
           echo "PROJECT_NUMBER=$PROJECT_NUMBER" >> $GITHUB_ENV
 
-      # https://github.com/marketplace/actions/doxygen-action
       - name: Build backend docs
         uses: mattnotmitt/doxygen-action@b84fe17600245bb5db3d6c247cc274ea98c15a3b # v1.12
         with:
@@ -187,7 +173,6 @@ jobs:
       - name: Copy backend docs
         run: cp -r dpnp/backend/doc/html ${{ env.PUBLISH_DIR }}/backend_doc
 
-      # https://github.com/marketplace/actions/github-pages-action
       # The step is only used to build docs while pushing a PR to "master"
       - name: Deploy docs
         if: env.GH_EVENT_PUSH_UPSTREAM == 'true'