diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0952fff..f87f523 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -104,7 +104,6 @@ jobs:
         with:
           micromamba-version: '1.5.1-0'
           environment-file: environment-dev.yaml
-          cache-environment: true
 
       - name: Install mamba
         run: conda install -c conda-forge mamba
@@ -138,7 +137,6 @@ jobs:
         with:
           micromamba-version: '1.5.1-0'
           environment-file: environment-dev.yaml
-          cache-environment: true
 
       - name: Install mamba
         run: conda install -c conda-forge mamba
@@ -193,7 +191,6 @@ jobs:
         with:
           micromamba-version: '1.5.1-0'
           environment-file: environment-dev.yaml
-          cache-environment: true
 
       - name: Install
         run: pip install jupyterlite_xeus*.whl
@@ -212,9 +209,6 @@ jobs:
         # try the latest stable and potential pre-releases
         jupyterlite_version: ["jupyterlite-core -U", "jupyterlite-core --pre"]
 
-    env:
-      PLAYWRIGHT_BROWSERS_PATH: ${{ github.workspace }}/pw-browsers
-
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -249,13 +243,6 @@ jobs:
         jlpm install
         jlpm run build
 
-    - name: Set up browser cache
-      uses: actions/cache@v3
-      with:
-        path: |
-          ${{ github.workspace }}/pw-browsers
-        key: ${{ runner.os }}-${{ hashFiles('ui-tests/yarn.lock') }}
-
     - name: Install browser
       run: jlpm playwright install chromium
       working-directory: ui-tests
diff --git a/pyproject.toml b/pyproject.toml
index 43640dc..b396c54 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
 ]
 dependencies = [
-    "empack>=3.1,<4",
+    "empack>=3.1,<5",
     "traitlets",
     "jupyterlite-core>=0.1,<0.5",
     "pyyaml",