The following function declarations can safely be removed because they're either unused or unneeded.

In Modules/_sqlite/cache.h:
pysqlite_node_init()     // unused; no function definition
pysqlite_node_dealloc()  // unneeded; file scope
pysqlite_cache_init()    // unneeded; file scope
pysqlite_cache_dealloc() // unneeded; file scope

In Modules/_sqlite/connection.h:
pysqlite_connection_alloc()    // unused; no function definition
pysqlite_connection_dealloc()  // unneeded; file scope
pysqlite_connection_cursor()   // unneeded; file scope
pysqlite_connection_close()    // unneeded; file scope
pysqlite_connection_rollback() // unneeded; file scope
pysqlite_connection_new()      // unused; no function definition
pysqlite_connection_init()     // unneeded; file scope

In Modules/_sqlite/cursor.h:
pysqlite_cursor_execute()     // unneeded; file scope
pysqlite_cursor_executemany() // unneeded; file scope
pysqlite_cursor_getiter()     // unused; no function definition
pysqlite_cursor_iternext()    // unneeded; file scope
pysqlite_cursor_fetchone()    // unneeded; file scope
pysqlite_cursor_fetchmany()   // unneeded; file scope
pysqlite_cursor_fetchall()    // unneeded; file scope
pysqlite_noop()               // unneeded; file scope
pysqlite_cursor_close()       // unneeded; file scope

In Modules/_sqlite/prepare_protocol.h:
pysqlite_prepare_protocol_init()    // unneeded; file scope
pysqlite_prepare_protocol_dealloc() // unneeded; file scope

In Modules/_sqlite/statement.h:
pysqlite_statement_dealloc() // unneeded; file scope