build: bump signal-hook from 0.3.8 to 0.3.9

Bumps [signal-hook](https://github.com/vorner/signal-hook) from 0.3.8 to 0.3.9.
- [Release notes](https://github.com/vorner/signal-hook/releases)
- [Changelog](https://github.com/vorner/signal-hook/blob/master/CHANGELOG.md)
- [Commits](https://github.com/vorner/signal-hook/compare/v0.3.8...v0.3.9)

---
updated-dependencies:
- dependency-name: signal-hook
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.lock

@@ -894,9 +894,9 @@ dependencies = [
 
 [[package]]
 name = "signal-hook"
-version = "0.3.8"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef33d6d0cd06e0840fba9985aab098c147e67e05cee14d412d3345ed14ff30ac"
+checksum = "470c5a6397076fae0094aaf06a08e6ba6f37acb77d3b1b91ea92b4d6c8650c39"
 dependencies = [
  "libc",
  "signal-hook-registry",
@@ -904,9 +904,9 @@ dependencies = [
 
 [[package]]
 name = "signal-hook-registry"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16f1d0fef1604ba8f7a073c7e701f213e056707210e9020af4528e0101ce11a6"
+checksum = "e51e73328dc4ac0c7ccbda3a494dfa03df1de2f46018127f60c693f2648455b0"
 dependencies = [
  "libc",
 ]