Bump tempfile from 3.3.0 to 3.4.0

Bumps [tempfile](https://github.com/Stebalien/tempfile) from 3.3.0 to 3.4.0.
- [Release notes](https://github.com/Stebalien/tempfile/releases)
- [Changelog](https://github.com/Stebalien/tempfile/blob/master/NEWS)
- [Commits](https://github.com/Stebalien/tempfile/commits)

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

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

bridges/relays/bin-substrate/Cargo.toml

@@ -65,5 +65,5 @@ xcm = { git = "https://github.com/paritytech/polkadot", branch = "master", defau
 bp-test-utils = { path = "../../primitives/test-utils" }
 hex-literal = "0.3"
 sp-keyring = { git = "https://github.com/paritytech/substrate", branch = "master" }
-tempfile = "3.2"
+tempfile = "3.4"
 finality-grandpa = { version = "0.16.0" }