feat: update ruby version to 3.3 #226

Job	Run time
test_course_definition / docker_lint	7s
test_course_definition / go_lint	3s
test_course_definition / identify_language_slugs	8s
test_course_definition / js_lint	23s
test_course_definition / markdown_lint	24s
test_course_definition / rust_lint	6s
test_course_definition / validate-schemas	21s
test_course_definition / validate-stages-naming	5s
test_course_definition / verify_templates_compiled	24s
test_course_definition / test (cpp)	42s
test_course_definition / test (csharp)	1m 6s
test_course_definition / test (go)	48s
test_course_definition / test (haskell)	1m 49s
test_course_definition / test (javascript)	24s
test_course_definition / test (python)	33s
test_course_definition / test (ruby)	25s
test_course_definition / test (rust)	50s
	8m 38s

Provide feedback