This update for matio fixes the following issues:

- update to version 1.5.29:
  * Fix printing rank-1-variable in Mat_VarPrint
  * Fix array index out of bounds in Mat_VarPrint when printing
    UTF-8 character data (boo#1239678, CVE-2025-2337)
  * Fix heap-based buffer overflow in strdup_vprintf
    (boo#1239677, CVE-2025-2338)
  * Changed Mat_VarPrint to print all values of rank-2-variable
  * Several other fixes, for example for access violations in
    Mat_VarPrint

- Update to version 1.5.28:
  * Fixed bug writing MAT_T_INT8/MAT_T_UINT8 encoded character
    array to compressed v5 MAT file (regression of v1.5.12).
  * Fixed bug reading all-zero sparse array of v4 MAT file
    (regression of v1.5.18).
  * Updated C99 snprintf.c.
  * CMake: Enabled testing.
  * Several other fixes, for example for access violations in
    Mat_VarPrint.