Python 3.6+ compatibility check workflow

Add workflow to check compatibility with minimum version 3.6.
Mention the supported versions in README.md.

.github/workflows/python.yml

@@ -26,7 +26,7 @@ jobs:
         with:
           python-version: "3.11"
       - name: Install Code Quality tools
-        run: pip install ruff flake8 mypy isort
+        run: pip install ruff flake8 mypy isort vermin
       - name: Ruff extremely fast Python linter and code formatter
         run: ruff check */*.py
       - name: Flake8 (with Black compatible settings)
@@ -35,3 +35,5 @@ jobs:
         run: mypy --strict */*.py
       - name: Isort imports alphabetically, separated into sections and by type
         run: isort --check --diff --profile black */*.py
+      - name: Features used compatible with Python 3.6
+        run: vermin --violations --target=3.6 .

README.md

@@ -12,11 +12,11 @@ Miscellaneous scripts for different purposes. Mostly unrelated to each other.
 | Email | [`mail-prepender.sh`](bin/mail-prepender.sh)<br>Shell (bash) | Prepends (to stdin/stdout) email header strings given in as flags `i`, `I`, `a`, or `A`; after possible mbox `From` & `Return-Path` header lines. Intended as a limited `formail` replacement that ignores the nyanses of the flags and simply prepends the valid (RFC 5322, 2.2) non-empty headers keeping the other headers as is. Flags `x` & `X` are implemented. Any other flags are ignored. |
 | Git | [`git-find-commits-by-file-hash.sh`](bin/git-find-commits-by-file-hash.sh)<br>Shell (bash) | Search Git repository history for commits with SHA-256 checksum of a file. Answers the question "Has this version of this file ever been committed as the file on this path of this Git repository?" and shows a summary (`git show --stat`) of the matching commit(s). The `path` should be relative to the repository root.<br>`git-find-commits-by-file-hash.sh sha256sum path`|
 | Infosec | [`netcat-proxy.sh`](bin/netcat-proxy.sh)<br>Shell (sh) | Creates a simple persistent TCP proxy with netcat & named pipes.<br>`netcat-proxy.sh listenport targethost targetport` |
-| Infosec | [`follow-cvelist.py`](bin/follow-cvelist.py)<br>Python 3 | Follow changes (commits) in CVEProject / [cvelistV5](https://github.com/CVEProject/cvelistV5). Requires git. Working directory must be the root of the cvelistV5 repository.<br>`follow-cvelist.py [-haForu4] [-vvvv] [-i s] [-c N] [-w N]`|
+| Infosec | [`follow-cvelist.py`](bin/follow-cvelist.py)<br>Python 3.6+ | Follow changes (commits) in CVEProject / [cvelistV5](https://github.com/CVEProject/cvelistV5). Requires git. Working directory must be the root of the cvelistV5 repository.<br>`follow-cvelist.py [-haForu4] [-vvvv] [-i s] [-c N] [-w N]`|
 | Infosec | [`partialpassword.sh`](bin/partialpassword.sh)<br>Shell (bash) | Creates a new wordlist from a wordlist by replacing all ambiguous characters with all their possible combinations.<br>`partialpassword.sh input.txt output.txt O0 [Il1 ...]` |
 | Infosec | [`duplicate-ssh-hostkeys.sh`](bin/duplicate-ssh-hostkeys.sh)<br>Shell (bash) | Find duplicate SSH host keys in a CIDR range. Examine your network for shared host keys that could potentially be dangerous.<br>`duplicate-ssh-hostkeys.sh CIDR [HostKeyAlgorithm ...]` |
-| Infosec<br>Automation | [`make-mac-prefixes.py`](bin/make-mac-prefixes.py)<br>Python 3 | Processes registered MAC address prefixes from [IEEE MA-L Assignments (CSV)](https://standards.ieee.org/products-programs/regauth/) (stdin) to Nmap's [`nmap-mac-prefixes`](https://github.com/nmap/nmap/blob/master/nmap-mac-prefixes)  (stdout) with a few additional unregistered OUIs.<br>`curl https://standards-oui.ieee.org/oui/oui.csv \| make-mac-prefixes.py > nmap-mac-prefixes` |
-| WordPress | [`test-cache-enabler.py`](bin/test-cache-enabler.py)<br>Python 3 | Tests whether the Cache Enabler by KeyCDN (WordPress) is working properly on the URLs given as arguments.<br>`test-cache-enabler.py https://example.com [...]` |
+| Infosec<br>Automation | [`make-mac-prefixes.py`](bin/make-mac-prefixes.py)<br>Python 3.6+ | Processes registered MAC address prefixes from [IEEE MA-L Assignments (CSV)](https://standards.ieee.org/products-programs/regauth/) (stdin) to Nmap's [`nmap-mac-prefixes`](https://github.com/nmap/nmap/blob/master/nmap-mac-prefixes)  (stdout) with a few additional unregistered OUIs.<br>`curl https://standards-oui.ieee.org/oui/oui.csv \| make-mac-prefixes.py > nmap-mac-prefixes` |
+| WordPress | [`test-cache-enabler.py`](bin/test-cache-enabler.py)<br>Python 3.6+ | Tests whether the Cache Enabler by KeyCDN (WordPress) is working properly on the URLs given as arguments.<br>`test-cache-enabler.py https://example.com [...]` |
 | Web | [`detect-modified-html-element.sh`](bin/detect-modified-html-element.sh)<br>Shell (bash) | Checks HTML element changes on a web page since last run. Configured via environment variables.<br>Recommended to be executed as a SystemD [service](systemd/detect-modified-html-element.service.example). |
 | Web | [`product-pricelimiter.sh`](bin/product-pricelimiter.sh)<br>Shell (bash) | Compare product price on a web page with a given maximum price. Use, e.g., developer tools on your browser to find the HTML element containing the price.<br>`product-pricelimiter.sh -u URL -s Selector [-m MaxPrice] [-n N] [-d N]` |
 | Web | <del>`koronarokotusaika.sh`</del><br>Shell (bash) | This script has been removed as koronarokotusaika.fi (bookcovidvaccine.fi) has been shut down on April 28, 2023. |