build: Bump once_cell from 1.14.0 to 1.15.0

Bumps [once_cell](https://github.com/matklad/once_cell) from 1.14.0 to 1.15.0.
- [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/v1.14.0...v1.15.0)

---
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

@@ -670,9 +670,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.14.0"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f7254b99e31cad77da24b08ebf628882739a608578bb1bcdfc1f9c21260d7c0"
+checksum = "e82dad04139b71a90c080c8463fe0dc7902db5192d939bd0950f074d014339e1"
 
 [[package]]
 name = "openssl-src"

Cargo.toml

@@ -47,7 +47,7 @@ versionize_derive = { git = "https://github.com/cloud-hypervisor/versionize_deri
 [dev-dependencies]
 dirs = "4.0.0"
 net_util = { path = "net_util" }
-once_cell = "1.14.0"
+once_cell = "1.15.0"
 serde_json = "1.0.85"
 test_infra = { path = "test_infra" }
 wait-timeout = "0.2.0"

net_util/Cargo.toml

@@ -22,7 +22,7 @@ vm-virtio = { path = "../vm-virtio" }
 vmm-sys-util = "0.10.0"
 
 [dev-dependencies]
-once_cell = "1.14.0"
+once_cell = "1.15.0"
 pnet = "0.31.0"
 pnet_datalink = "0.31.0"
 serde_json = "1.0.85"

test_infra/Cargo.toml

@@ -8,7 +8,7 @@ edition = "2021"
 dirs = "4.0.0"
 epoll = "4.3.1"
 libc = "0.2.133"
-once_cell = "1.14.0"
+once_cell = "1.15.0"
 serde = { version = "1.0.144", features = ["rc", "derive"] }
 serde_json = "1.0.85"
 ssh2 = { version = "0.9.3", features = ["vendored-openssl"] }

vmm/Cargo.toml

@@ -32,7 +32,7 @@ linux-loader = { version = "0.5.0", features = ["elf", "bzimage", "pe"] }
 log = "0.4.17"
 micro_http = { git = "https://github.com/firecracker-microvm/micro-http", branch = "main" }
 net_util = { path = "../net_util" }
-once_cell = "1.14.0"
+once_cell = "1.15.0"
 option_parser = { path = "../option_parser" }
 pci = { path = "../pci" }
 qcow = { path = "../qcow" }