Draft: Changes for compatibility with pystencils 2.0

Introduce a significant number of patches for compatibility with the upcoming pystencils 2.0.

Status:

• Fix field duplication in create_lb_update_rule: Remove the workaround once field duplication is fixed in pystencils
• Data types in boundary handling: LatticeBoltzmannBoundaryHandling does not allow to specify a data type and always uses float64. This leads to type errors when combined with LB fields with float32 dtype.
• Mixed precision: Need to explicitly insert casts at field reads/writes when computing and storing PDFs in different float formats

.gitlab-ci.yml

 stages:
   - pretest
   - test
+  - prerelease
   - nightly
   - docs
   - deploy
@@ -211,6 +212,35 @@ pycodegen-integration:
     - cuda11
     - AVX
 
+# -------------------- pystencils Pre-Release --------------------------------------------------------------------------
+
+
+pystencils-2.0dev:
+  stage: prerelease
+  extends: .every-commit
+  image: i10git.cs.fau.de:5005/pycodegen/pycodegen/full
+  allow_failure: true
+  needs: []
+  before_script:
+    - pip install sympy --upgrade 
+    - pip install git+https://gitlab-ci-token:${CI_JOB_TOKEN}@i10git.cs.fau.de/pycodegen/pystencils.git@v2.0-dev#egg=pystencils
+  script:
+    - export NUM_CORES=$(nproc --all)
+    - mkdir -p ~/.config/matplotlib
+    - echo "backend:template" > ~/.config/matplotlib/matplotlibrc
+    - env
+    - pip list
+    - py.test -v -n $NUM_CORES -m "not longrun" --junitxml=report.xml
+  tags:
+    - docker
+    - AVX
+    - cuda11
+  artifacts:
+    when: always
+    reports:
+      junit: report.xml
+
+
 # -------------------- Scheduled Tasks --------------------------------------------------------------------------