Fix beta workflow (#1366)

* MAINT: Fix beta workflow

* MAINT: Install compatible NumPy

* MAINT: Revert temporary change

Author: mattwthompson

.github/workflows/beta.yaml

@@ -2,7 +2,7 @@ name: Tests against betas
 
 on:
   schedule:
-    - cron: "0 3 * * *"
+    - cron: "0 17 * * *"
   workflow_dispatch:
 
 defaults:
@@ -62,6 +62,10 @@ jobs:
       env:
         SECRET_OE_LICENSE: ${{ secrets.OE_LICENSE }}
 
+    - name: Install AmberTools
+      if: ${{ matrix.openeye == false }}
+      run: micromamba install "ambertools =24" -c conda-forge
+
     - name: Run mypy
       run: mypy --show-error-codes --namespace-packages -p "openff.interchange"