build(deps): bump once_cell from 1.7.2 to 1.8.0

Bumps [once_cell](https://github.com/matklad/once_cell) from 1.7.2 to 1.8.0.
- [Release notes](https://github.com/matklad/once_cell/releases)
- [Changelog](https://github.com/matklad/once_cell/blob/master/CHANGELOG.md)
- [Commits](https://github.com/matklad/once_cell/compare/v1.7.2...v1.8.0)

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

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

Cargo.lock

@@ -2243,9 +2243,9 @@ checksum = "8d3b63360ec3cb337817c2dbd47ab4a0f170d285d8e5a2064600f3def1402397"
 
 [[package]]
 name = "once_cell"
-version = "1.7.2"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
 
 [[package]]
 name = "oorandom"

zebra-consensus/Cargo.toml

@@ -14,7 +14,7 @@ chrono = "0.4.19"
 displaydoc = "0.2.1"
 jubjub = "0.6.0"
 lazy_static = "1.4.0"
-once_cell = "1.7"
+once_cell = "1.8"
 pairing = "0.19.0"
 rand = "0.8"
 serde = { version = "1", features = ["serde_derive"] }

zebra-state/Cargo.toml

@@ -34,7 +34,7 @@ zebra-chain = { path = "../zebra-chain", features = ["proptest-impl"] }
 zebra-test = { path = "../zebra-test/" }
 
 color-eyre = "0.5.11"
-once_cell = "1.7"
+once_cell = "1.8"
 spandoc = "0.2"
 tempdir = "0.3.7"
 tokio = { version = "0.3.6", features = ["full"] }

zebrad/Cargo.toml

@@ -52,7 +52,7 @@ vergen = { version = "5.1.8", default-features = false, features = ["cargo", "gi
 
 [dev-dependencies]
 abscissa_core = { version = "0.5", features = ["testing"] }
-once_cell = "1.7"
+once_cell = "1.8"
 regex = "1.4.6"
 semver = "1.0.3"
 tempdir = "0.3.7"