Document Q1 2025 releases

11.4.5:
MDEV-35256 Alias MySQL 900 collations into MariaDB 1400 collations

11.8.1:
MDEV-9158 file_key_management should support reading from a named pipe
MDEV-10862 Stored procedures: default values for parameters (optional parameters)
MDEV-22217 Make OS character sets "utf8" and "utf-8" map to MariaDB character set "utf8mb4"
MDEV-30469 Support ORDER BY and LIMIT for multi-table DELETE, index hints for single-table DELETE.
MDEV-34317 DECLARE TYPE type_name IS RECORD (..) with scalar members in stored routines
MDEV-34551 Column list in the trigger definition
MDEV-34699 mhnsw: support aarch64 SIMD instructions
MDEV-34724 Skipping a row operation from a trigger
MDEV-34740 mariadb-import: delay creation of secondary indexes until after data load
MDEV-34911 Make SUBSTR(col, 1, n) = const_str sargable
MDEV-35049 fix innodb-adaptive-hash-index scalability with multiple threads
MDEV-35450 VEC_DISTANCE() function to autouse the available index type
MDEV-35616 Add basic optimizer support for virtual columns