Bump dependencies: pyo3, rusqlite, rand

[brenordv]

From this report, I noticed that a handful of dependencies are outdated, so I updated some, starting from the simplest.
No behavior change, and minimal code change was required.

Changes Summary

Dependency Bumps

Package	Crate	Section	Old	New
rand	redb (root)	[dev-dependencies]	0.9	0.10.0
rusqlite	redb-bench	[dependencies]	0.37	0.38.0
pyo3	redb-python	[dependencies]	0.24.1	0.28.1
pyo3-build-config	redb-python	[build-dependencies]	0.24.1	0.28.1

Code Adjustments (required by rand 0.9 -> 0.10 API change)

In rand 0.10, methods random(), random_range(), and random_bool() moved from the
Rng trait to the new RngExt trait. Two files updated:

• tests/integration_tests.rs: use rand::Rng -> use rand::RngExt
• src/tree_store/page_store/bitmap.rs: use rand::{Rng, SeedableRng} -> use rand::{RngExt, SeedableRng}

Files Changed (5 total)

1. Cargo.toml - bump rand
2. crates/redb-bench/Cargo.toml - bump rusqlite
3. crates/redb-python/Cargo.toml - bump pyo3 + pyo3-build-config
4. src/tree_store/page_store/bitmap.rs - rand::Rng -> rand::RngExt (test code)
5. tests/integration_tests.rs - rand::Rng -> rand::RngExt

---

Verification

All checks performed with RUSTFLAGS="--deny warnings".

• redb-bench: Could not build locally due to WSL2 cross-filesystem permission errors in native C library build scripts (libsqlite3-sys, lz4-sys, librocksdb-sys). This is an environment limitation, not a code issue. CI runners on native Ubuntu/macOS/Windows will build this crate without issue. The Rust-level cargo check for the bench crate itself succeeded (the failure is only in the C library linking phase).

• redb-python: Compilation and clippy verified. Full Python wrapper tests (just test_py)
  require CPython 3.12 + maturin which will run in CI.

• pyo3 0.24 -> 0.28: No code changes needed; abi3-py37 feature and extension-module
  feature both compile cleanly.

• rusqlite 0.37 -> 0.38: No code changes needed in the benchmark crate.