Bump base64 from 0.13.1 to 0.21.2

Bumps [base64](https://github.com/marshallpierce/rust-base64) from 0.13.1 to 0.21.2.
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](marshallpierce/rust-base64@v0.13.1...v0.21.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.lock

@@ -40,7 +40,7 @@ ahash = "0.8.0"
 url = "2.3.1"
 # idna is already required by url, added here to be explicit
 idna = "0.3.0"
-base64 = "0.13.1"
+base64 = "0.21.2"
 num-bigint = "0.4.3"
 python3-dll-a = "0.2.7"