chore: require Python ≥3.9

Author: vchudnov-g

.github/workflows/tests.yaml

@@ -53,7 +53,7 @@ jobs:
       matrix:
         # Run mypy on all of the supported python versions listed in setup.py
         # https://github.com/python/mypy/blob/master/setup.py
-        python: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -71,13 +71,11 @@ jobs:
       # Run showcase tests on the lowest and highest supported runtimes
       matrix:
         # TODO(https://github.com/googleapis/gapic-generator-python/issues/2121) Remove `showcase_w_rest_async` target when async rest is GA.
-        python: ["3.7", "3.13"]
+        python: ["3.9", "3.13"]
         target: [showcase, showcase_w_rest_async]
         logging_scope: ["", "google"]
 
-    # TODO(https://github.com/googleapis/gapic-generator-python/issues/2303): use `ubuntu-latest` once this bug is fixed.
-    # Use ubuntu-22.04 until Python 3.7 is removed from the test matrix
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python "${{ matrix.python }}"
@@ -162,14 +160,12 @@ jobs:
   showcase-unit:
     strategy:
       matrix:
-        python: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
         # TODO(https://github.com/googleapis/gapic-generator-python/issues/2121) Remove `_w_rest_async` variant when async rest is GA.
         variant: ['', _alternative_templates, _mixins, _alternative_templates_mixins, _w_rest_async]
         logging_scope: ["", "google"]
 
-    # TODO(https://github.com/googleapis/gapic-generator-python/issues/2303): use `ubuntu-latest` once this bug is fixed.
-    # Use ubuntu-22.04 until Python 3.7 is removed from the test matrix
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python "${{ matrix.python }}"
@@ -269,11 +265,9 @@ jobs:
   unit:
     strategy:
       matrix:
-        python: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
 
-    # TODO(https://github.com/googleapis/gapic-generator-python/issues/2303): use `ubuntu-latest` once this bug is fixed.
-    # Use ubuntu-22.04 until Python 3.7 is removed from the test matrix
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python }}
@@ -293,12 +287,10 @@ jobs:
   fragment:
     strategy:
       matrix:
-        python: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
         variant: ['', _alternative_templates]
 
-    # TODO(https://github.com/googleapis/gapic-generator-python/issues/2303): use `ubuntu-latest` once this bug is fixed.
-    # Use ubuntu-22.04 until Python 3.7 is removed from the test matrix
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python }}

DEVELOPMENT.md

@@ -18,7 +18,7 @@
 
 Execute unit tests by running one of the sessions prefixed with `unit-`.
 
--   Example: `nox -s unit-3.8`
+-   Example: `nox -s unit-3.13`
 -   See all Nox sessions with `nox -l`.
 
 ## Formatting

noxfile.py

@@ -37,8 +37,6 @@
 BLACK_EXCLUDES = "|".join([".*golden.*", ".*pb2.py"])
 
 ALL_PYTHON = (
-    "3.7",
-    "3.8",
     "3.9",
     "3.10",
     "3.11",