sqlite3.Connection.iterdump() produces an unrestorable dump for a populated virtual table

Bug description

sqlite3.Connection.iterdump() emits INSERT statements for a virtual table's
own rows in addition to its schema. Those rows live in the shadow tables (which
are dumped separately), and on restore they run before the virtual table module
is instantiated, so restoring the dump fails:

import sqlite3
src = sqlite3.connect(":memory:")
src.execute("CREATE VIRTUAL TABLE t USING fts4(x)")
src.execute("INSERT INTO t(x) VALUES ('hello world')")
script = "".join(src.iterdump())
dst = sqlite3.connect(":memory:")
dst.executescript(script)
# sqlite3.OperationalError: no such table: t

The SQLite shell's .dump does not emit content rows for virtual tables.

CPython versions tested on

3.14, 3.15, 3.16

Operating systems tested on

macOS

Linked PRs

• gh-153730

首先通过 sqlite3.Connection.iterdump() 重现该示例，并将其输出与 SQLite 的 .dump 行为进行比较。完成的标准是：来自已填充虚拟表的 dump 可以在新连接上执行，而不会出现报告的 no such table 故障；开始前请检查已关联的 PR gh-153730，因为这项工作已经与该 issue 关联。