fix(git-lib): avoid regex error with non-ASCII branch names

_omz_git_prompt_status was emitting "regex matching error: illegal byte
sequence" when the git branch name contained non-ASCII characters (e.g.
Chinese). The zsh =~ operator uses locale-aware POSIX ERE, so character
classes like [^ ]+ reject multibyte sequences unless LC_ALL=C is set.
Fix by setting LC_ALL=C around all regex operations in the function and
restoring it afterwards.

Fixes #13330

lib/git.zsh

@@ -103,6 +103,11 @@ function _omz_git_prompt_status() {
   local status_lines
   status_lines=("${(@f)${status_text}}")
 
+  # Use C locale for regex matching to avoid "illegal byte sequence" errors
+  # when branch names or file paths contain non-ASCII characters (e.g. Chinese)
+  local _omz_lc_all=$LC_ALL
+  LC_ALL=C
+
   # If the tracking line exists, get and parse it
   if [[ "$status_lines[1]" =~ "^## [^ ]+ \[(.*)\]" ]]; then
     local branch_statuses
@@ -126,6 +131,8 @@ function _omz_git_prompt_status() {
     fi
   done
 
+  LC_ALL=$_omz_lc_all
+
   # Display the seen statuses in the order specified
   local status_prompt
   for status_constant in $status_constants; do