fix(deps): update rust crate base64 to 0.23

[ktjn]

This PR contains the following updates:

Package	Type	Update	Change
base64	dependencies	minor	0.22 → 0.23

---

Release Notes

marshallpierce/rust-base64 (base64)

v0.23.0

Compare Source

• Added more consts for preconfigured configs and engines
• Make DecodeError::InvalidLastSymbol more clear by including the decoded value
• Added SIMD-accelerated engines behind the default-on simd-unsafe feature: Simd picks the best
  instruction set at runtime (AVX2 on x86_64, NEON on aarch64) and falls back to the scalar
  GeneralPurpose engine, while Avx2 and Neon target one instruction set with no runtime
  detection and work in no_std. The engines support the standard and URL-safe alphabets.
• Update MSRV to 1.71.0
• Add support for custom padding symbols

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • At any time (no schedule defined)
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate.