Upgrade python requirement to 3.9

Author: timwoj

.github/workflows/btest.yml

@@ -12,7 +12,7 @@ jobs:
   Run-BTest:
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: [macos-latest, ubuntu-latest, windows-latest]
 
     runs-on: ${{ matrix.os }}
@@ -53,7 +53,7 @@ jobs:
   Test-SetupPY:
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: [ubuntu-latest]
 
     runs-on: ${{ matrix.os }}

README

@@ -27,8 +27,7 @@ Prerequisites
 
 BTest has the following prerequisites:
 
-- Python version >= 3.7 (older versions may work, but are not
-  well-tested).
+- Python version >= 3.9 (older versions may work, but are not well-tested).
 
 - Bash. Note that on FreeBSD and Alpine Linux, bash is not installed by
   default. This is also required on Windows, in the form of Git's msys2, Cygwin,

pyproject.toml

@@ -9,7 +9,7 @@ dynamic = ["version"]
 
 license = { text = "3-clause BSD License" }
 
-requires-python = ">=3.7"
+requires-python = ">=3.9"
 
 keywords=[
     "system",