build(deps): bump base64 from 0.2.1 to 0.21.7

Bumps [base64](https://github.com/marshallpierce/rust-base64) from 0.2.1 to 0.21.7.
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](marshallpierce/rust-base64@v0.2.1...v0.21.7)

---
updated-dependencies:
- dependency-name: base64
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.lock

@@ -171,7 +171,7 @@ arrayvec = "0.7"
 num-bigint = "0.4.6"
 num-traits = "0.2.19"
 zerocopy = { version = "0.8.20" }
-base64 = "0.13"
+base64 = "0.22"
 zeroize = "=1.3.0"
 
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