ci: pin micromamba version and bump Pyodide version (#1633)

* Pin micromamba version until there is a new release

* Try pinning pydantic

* Bump pyodide version

Author: ariostas

.github/workflows/build-test.yml

@@ -38,6 +38,7 @@ jobs:
             --strict-channel-priority
             conda-forge/label/python_rc::_python_rc
             python=${{ matrix.python-version }}
+          micromamba-version: 2.6.0-0   # unpin when there is a release newer than 2.6.1-0
 
       - name: Set PYTHON_GIL=0 for free-threaded builds
         if: contains(matrix.python-version, 'python-freethreading')
@@ -139,8 +140,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     env:
-      PYODIDE_VERSION: 0.28.1
-      PYODIDE_BUILD_VERSION: 0.30.5
+      PYODIDE_VERSION: 0.29.4
+      PYODIDE_BUILD_VERSION: 0.34.4
       AWKWARD_VERSION: v2.8.5
 
     steps: