fix(lib/git): turn off async prompt for zsh < 5.0.6

We removed this mitigation in 0c80a063 because of an assumption
that the issue had been fixed, but it looks like zsh < 5.0.6 has
other issues (see #12360), so we need to disable it for real.

Fixes #12360

lib/git.zsh

@@ -39,8 +39,13 @@ function _omz_git_prompt_info() {
   echo "${ZSH_THEME_GIT_PROMPT_PREFIX}${ref:gs/%/%%}${upstream:gs/%/%%}$(parse_git_dirty)${ZSH_THEME_GIT_PROMPT_SUFFIX}"
 }
 
-# Use async version if setting is enabled or undefined
+# Use async version if setting is enabled, or unset but zsh version is at least 5.0.6.
-if zstyle -T ':omz:alpha:lib:git' async-prompt; then
+# This avoids async prompt issues caused by previous zsh versions:
+# - https://github.com/ohmyzsh/ohmyzsh/issues/12331
+# - https://github.com/ohmyzsh/ohmyzsh/issues/12360
+# TODO(2024-06-12): @mcornella remove workaround when CentOS 7 reaches EOL
+if zstyle -t ':omz:alpha:lib:git' async-prompt \
+  || { is-at-least 5.0.6 && zstyle -T ':omz:alpha:lib:git' async-prompt }; then
   function git_prompt_info() {
     if [[ -n "${_OMZ_ASYNC_OUTPUT[_omz_git_prompt_info]}" ]]; then
       echo -n "${_OMZ_ASYNC_OUTPUT[_omz_git_prompt_info]}"