[Doc] Updates @since and @before tags to 26.0-Iron.

src/kernel_internals/runtime/fc_config.mli

src/kernel_services/ast_data/alarms.mli

src/kernel_services/ast_data/annotations.mli

src/kernel_services/ast_data/kernel_function.mli

src/kernel_services/ast_queries/ast_info.mli

src/kernel_services/ast_queries/cil.mli

src/kernel_services/plugin_entry_points/db.mli

src/kernel_services/plugin_entry_points/dynamic.mli

src/kernel_services/plugin_entry_points/kernel.mli

src/libraries/datatype/datatype.mli