gh-46927: Prevent readline from overriding environment variables (GH-153184)

gh-46927: Prevent readline from overriding environment variables (GH-153184)

Readline sets COLUMNS and LINES to the terminal size at initialization, and
ncurses prefers those stale variables over an ioctl() query, breaking resize
handling. Set rl_change_environment to 0, when available, so importing
readline no longer modifies the environment.

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>