Drop support of Emacs 24

Author: taku0

.github/workflows/run-test.yml

@@ -32,8 +32,6 @@ jobs:
  - '26.1'
  - '25.3'
  - '25.2'
- - '24.5'
- - '24.4'
  - 'snapshot'
 
  env:

scripts/lint_in_docker.sh

@@ -3,7 +3,7 @@
 # Run linter in Docker. Used in Makefile.
 
 # Indentation rules changed since 29.
-for version in 30 29 # 28 27 26 25 24
+for version in 30 29 # 28 27 26 25
 do
  docker \
  run \

scripts/test_in_docker.sh

@@ -2,7 +2,7 @@
 
 # Run tests in Docker. Used in Makefile.
 
-for version in 30 29 28 27 26 25 24
+for version in 30 29 28 27 26 25
 do
  rm -f *.elc test/*.elc
  rm -f *-autoloads.el

swift-mode.el

@@ -10,7 +10,7 @@
 ;; Maintainer: taku0 <mxxouy6x3m_github@tatapa.org>
 ;;
 ;; Version: 9.4.0
-;; Package-Requires: ((emacs "24.4") (seq "2.3"))
+;; Package-Requires: ((emacs "25.2"))
 ;; Keywords: languages swift
 ;; URL: https://github.com/swift-emacs/swift-mode