Merge branch 'remove-python38' of https://github.com/googleapis/python-documentai-toolbox into remove-python38

Author: gcf-owl-bot[bot]

.github/workflows/unittest.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
+        python: ['3.9', '3.13', '3.14']
     steps:
     - name: Checkout
       uses: actions/checkout@v4

noxfile.py

@@ -71,9 +71,6 @@
 
 nox.options.sessions = [
     "unit-3.9",
-    "unit-3.10",
-    "unit-3.11",
-    "unit-3.12",
     "unit-3.13",
     "unit-3.14",
     "system",