chore(deps): bump handlebars from 3.5.5 to 4.1.2

Bumps [handlebars](https://github.com/sunng87/handlebars-rust) from 3.5.5 to 4.1.2.
- [Release notes](https://github.com/sunng87/handlebars-rust/releases)
- [Changelog](https://github.com/sunng87/handlebars-rust/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sunng87/handlebars-rust/compare/v3.5.5...v4.1.2)

---
updated-dependencies:
- dependency-name: handlebars
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Cargo.lock

@@ -1475,9 +1475,9 @@ checksum = "62aca2aba2d62b4a7f5b33f3712cb1b0692779a56fb510499d5c0aa594daeaf3"
 
 [[package]]
 name = "handlebars"
-version = "3.5.5"
+version = "4.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4498fc115fa7d34de968184e473529abb40eeb6be8bc5f7faba3d08c316cb3e3"
+checksum = "fd85ecabdb47308d28d3a4113224fefcab2510ccb4e463aee0a1362eb84c756a"
 dependencies = [
  "log",
  "pest",

iox_data_generator/Cargo.toml

@@ -10,7 +10,7 @@ chrono = "0.4.13"
 chrono-english = "0.1.4"
 clap = "2.33.1"
 futures = "0.3.5"
-handlebars = "3.3.0"
+handlebars = "4.1.2"
 data_types = { path = "../data_types" }
 generated_types = { path = "../generated_types" }
 influxdb2_client = { path = "../influxdb2_client" }