Run CI builds on Python 3.11 (#3825)

* Ensure valid atom order after loading a checkpoint

* Run CI builds on Python 3.11

.github/workflows/CI.yml

@@ -121,8 +121,8 @@ jobs:
               -DOPENMM_BUILD_OPENCL_LIB=OFF \
               -DOPENMM_BUILD_OPENCL_TESTS=OFF \
 
-          - name: Linux CPU Python 3.10
-            python-version: "3.10"
+          - name: Linux CPU Python 3.11
+            python-version: "3.11"
             os: ubuntu-latest
             OPENCL: false
             cuda-version: ""
@@ -139,8 +139,8 @@ jobs:
               -DOPENMM_BUILD_OPENCL_LIB=OFF \
               -DOPENMM_BUILD_OPENCL_TESTS=OFF \
 
-          - name: MacOS Intel CPU/OpenCL Python 3.10
-            python-version: "3.10"
+          - name: MacOS Intel CPU/OpenCL Python 3.11
+            python-version: "3.11"
             os: macos-latest
             OPENCL: false
             cuda-version: ""
@@ -148,8 +148,8 @@ jobs:
               -DOPENMM_BUILD_OPENCL_LIB=ON \
               -DOPENMM_BUILD_OPENCL_TESTS=OFF \
 
-          - name: MacOS M1 CPU arm64 Python 3.10
-            python-version: "3.10"
+          - name: MacOS M1 CPU arm64 Python 3.11
+            python-version: "3.11"
             os: M1-arm64
             OPENCL: false
             cuda-version: ""
@@ -322,8 +322,8 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - name: Windows CUDA 11.2 Python 3.10
-            python-version: "3.10"
+          - name: Windows CUDA 11.2 Python 3.11
+            python-version: "3.11"
             cuda-version: "11.2"
             CMAKE_FLAGS: |
               -DCUDA_TOOLKIT_ROOT_DIR="%CUDA_TOOLKIT_ROOT_DIR%" ^
@@ -458,19 +458,19 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - name: PowerPC CPU/CUDA 10.2 Python 3.10 with condaforge compilers
+          - name: PowerPC CPU/CUDA 10.2 Python 3.11 with condaforge compilers
             docker-image: quay.io/condaforge/linux-anvil-ppc64le-cuda:10.2
-            python-version: "3.10"
+            python-version: "3.11"
             compilers: compilers
 
-          - name: PowerPC CPU Python 3.10 devtoolset-7 compilers
+          - name: PowerPC CPU Python 3.11 devtoolset-7 compilers
             docker-image: quay.io/condaforge/linux-anvil-ppc64le
-            python-version: "3.10"
+            python-version: "3.11"
             compilers: devtoolset-7
 
-          - name: ARM CPU Python 3.10 with condaforge compilers
+          - name: ARM CPU Python 3.11 with condaforge compilers
             docker-image: quay.io/condaforge/linux-anvil-aarch64
-            python-version: "3.10"
+            python-version: "3.11"
             compilers: compilers