Require Ruby >= 3.2.0 (closes #199).

* Ruby 3.1 has reached End-of-Life and the new `io-endpoint` and
  `io-stream` gems require Ruby >= 3.2.0.

Author: postmodern

.github/workflows/ruby.yml

@@ -9,7 +9,6 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-          - '3.1'
           - '3.2'
           - '3.3'
           - '3.4'

README.md

@@ -302,7 +302,7 @@ end
 
 ## Requirements
 
-* [Ruby] >= 3.1.0
+* [Ruby] >= 3.2.0
 * [nmap] >= 5.00
 * [GraphViz][graphviz] (for SVG, PNG, or PDF output)
 * [thread-local] ~> 1.0

gemspec.yml

@@ -36,7 +36,7 @@ generated_files:
  - data/wordlists/subdomains-1000.txt.gz
  - data/wordlists/raft-small-directories.txt.gz
 
-required_ruby_version: ">= 3.1.0"
+required_ruby_version: ">= 3.2.0"
 
 dependencies:
   csv: ~> 3.0