fix(sqlite): disable positional indexing when sqlc.slice is present

[noxymon]

hopefully fixes #4213

Problem:

In SQLite, sqlc uses positional parameters (e.g., ?1, ?2) to support named parameter reuse. However, sqlc.slice expands at runtime into a variable number of placeholders via strings.Replace. If a named parameter follows a slice, its compile-time
index (e.g., ?2) becomes invalid at runtime because the slice expansion shifted the actual argument positions in the underlying driver call. This leads to runtime data corruption as parameters pick up the wrong values.

Solution:

This PR modifies the SQLite rewriter to detect if a sqlc.slice is present in the query. If a slice is detected, named parameter support (positional indexing) is disabled for that specific query. This forces the rewriter to use simple ? placeholders
and the Go generator to append every parameter occurrence to the queryParams slice. This approach is inherently safe against dynamic placeholder expansion and matches the proven behavior of the MySQL generator.

Verification:

• Reproduction: Created internal/endtoend/testdata/issue_4213_repro to confirm the bug.
• Regression: Verified that named parameter reuse still works (via duplication in the arg list) in internal/endtoend/testdata/issue_4213_reuse.
• Existing Tests: Updated sqlc_slice and sqlc_slice_prepared end-to-end tests for SQLite which were previously expecting the broken positional behavior.
• Test Suite: All SQLite end-to-end tests are passing.