Drop Python 3.7 and support only Python 3.8+

Python 3.7 is EOL, and updated versions of some dependencies, such as
pylint 3, only support Python 3.8+. Drop Python 3.7 in preparation to
update those dependencies, which in turn should enable support for
Python 3.11 and 3.12.

Author: RytoEX

.github/workflows/all-lints.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ['3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.8', '3.9', '3.10']
     steps:
     - uses: actions/checkout@v1
     - uses: marian-code/python-lint-annotate@master

README.md

@@ -46,15 +46,15 @@ steps:
       use-mypy: false
       use-vulture: true
       extra-pylint-options: "--output-format="colorized"
-      python-version: "3.7"
+      python-version: "3.8"
 ```
 
 ### Examples
 * [Only lint changed files, and ignore missing docstrings](examples/actions-only_changed_files.yml)
 
 ## Details
 
-Uses `actions/setup-python@v2`. Only python `3.7` - `3.10` version are tested since
+Uses `actions/setup-python@v2`. Only python `3.8` - `3.10` version are tested since
 they are by far most common now. Other python `3.x` versions should also work.
 Any python `2.x` versions are unsupported! You can lint on Linux, Windows and MacOS.
 
@@ -112,9 +112,9 @@ jobs:
         use-pylint: false
         use-flake8: false
         use-vulture: true
-        python-version: "3.7"
+        python-version: "3.8"
     - run: |
-        python --version  # this will output 3.7 now !!!
+        python --version  # this will output 3.8 now !!!
 ```
 
 ## License