DO NOT MERGE: pip-install nutpie from main in all CI jobs

Temporary experiment to see whether pinning every CI job to nutpie's git
main is viable, or whether it would make the whole suite too fragile
(since main can break unrelated to pymc changes). If CI is green we can
consider making it permanent; otherwise drop this commit and keep the
alt_backends job as the lone canary.

Author: ricardoV94

.github/workflows/tests.yml

@@ -168,6 +168,8 @@ jobs:
         run: |
           pip install "pytensor @ git+https://github.com/pymc-devs/pytensor.git@v3" --no-deps
           pip install -e . --no-deps
+          # Track nutpie main to catch any incompatibility with pymc early.
+          pip install "nutpie @ git+https://github.com/pymc-devs/nutpie@main"
           python --version
           micromamba list
       - name: Run tests
@@ -218,6 +220,8 @@ jobs:
         run: |
           pip install "pytensor @ git+https://github.com/pymc-devs/pytensor.git@v3" --no-deps
           pip install -e . --no-deps
+          # Track nutpie main to catch any incompatibility with pymc early.
+          pip install "nutpie @ git+https://github.com/pymc-devs/nutpie@main"
           python --version
           micromamba list
       - name: Run tests
@@ -276,6 +280,8 @@ jobs:
         run: |
           pip install "pytensor @ git+https://github.com/pymc-devs/pytensor.git@v3" --no-deps
           pip install -e . --no-deps
+          # Track nutpie main to catch any incompatibility with pymc early.
+          pip install "nutpie @ git+https://github.com/pymc-devs/nutpie@main"
           python --version
           micromamba list
       - name: Run tests
@@ -378,6 +384,8 @@ jobs:
         run: |
           pip install "pytensor @ git+https://github.com/pymc-devs/pytensor.git@v3" --no-deps
           pip install -e . --no-deps
+          # Track nutpie main to catch any incompatibility with pymc early.
+          pip install "nutpie @ git+https://github.com/pymc-devs/nutpie@main"
           python --version
           micromamba list
       - name: Run tests