deprecating python 3.9 and package version bumps

.github/workflows/pull_request.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.10"]
+        python-version: ["3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v3
@@ -23,10 +23,10 @@ jobs:
       # manually if/when you want to upgrade Poetry, or if something goes wrong. This could be
       # mildly cleaner by using an environment variable, but I don't really care.
       - name: cache poetry install
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ~/.local
-          key: poetry-1.1.12-0
+          key: poetry-2.3.3-0
 
       # Install Poetry. You could do this manually, or there are several actions that do this.
       # `snok/install-poetry` seems to be minimal yet complete, and really just calls out to
@@ -39,7 +39,7 @@ jobs:
       # cache it.
       - uses: snok/install-poetry@v1
         with:
-          version: 1.5.1
+          version: 2.3.3
           virtualenvs-create: true
           virtualenvs-in-project: true
 
@@ -48,7 +48,7 @@ jobs:
       # them in the cache key. I'm not, so it can be simple and just depend on the poetry.lock.
       - name: cache deps
         id: cache-deps
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: .venv
           key: pydeps-${{ hashFiles('**/poetry.lock') }}