Upgrade core Actions majors and declare python_requires

Author: ChrisChilders-USDA

.github/workflows/build.yml

@@ -13,9 +13,9 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Python 3.9
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.9"
       - name: Install dependencies
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -60,9 +60,9 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Python 3.9
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.9"
       - name: Install dependencies

setup.py

@@ -161,6 +161,9 @@ def run(self):
     # Note that this is a string of words separated by whitespace, not a list.
     keywords='gff3 gff bioinformatics ',  # Optional
 
+    # Explicitly declare supported runtime versions for installers and tools.
+    python_requires='>=3.9',
+
     # You can just specify package directories manually here if your project is
     # simple. Or you can use find_packages().
     #