Compose buffer resizes after increasing it's height

### OS/platform Linux ### Emacs version and provenance 31.x ### Emacs command emacs --fg-daemon ### Emacs frame type X ### Ement package version and provenance latest master ### Actions taken 1. C-' 2. Resize window 3. Type 4. Window size is reduced. ### Observed results When trying to use compose buffer I like to increase its height beyond the default sometimes. After doing that and then typing the size is reduced again after a while. ### Expected results That it doesn't go below the size I changed the compose buffer into. ### Backtrace ```elisp ``` ### Etc. _No response_