Bump exr from 1.5.3 to 1.6.3

Bumps [exr](https://github.com/johannesvollmer/exrs) from 1.5.3 to 1.6.3.
- [Release notes](https://github.com/johannesvollmer/exrs/releases)
- [Commits](https://github.com/johannesvollmer/exrs/commits)

---
updated-dependencies:
- dependency-name: exr
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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

Cargo.lock

@@ -1594,17 +1594,17 @@ dependencies = [
 
 [[package]]
 name = "exr"
-version = "1.5.3"
+version = "1.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8af5ef47e2ed89d23d0ecbc1b681b30390069de70260937877514377fc24feb"
+checksum = "bdd2162b720141a91a054640662d3edce3d50a944a50ffca5313cd951abb35b4"
 dependencies = [
  "bit_field",
  "flume",
  "half 2.2.1",
  "lebe",
  "miniz_oxide 0.6.2",
+ "rayon-core",
  "smallvec",
- "threadpool",
  "zune-inflate",
 ]
 
@@ -6524,15 +6524,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "threadpool"
-version = "1.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d050e60b33d41c19108b32cea32164033a9013fe3b46cbd4457559bfbf77afaa"
-dependencies = [
- "num_cpus",
-]
-
 [[package]]
 name = "thunderdome"
 version = "0.3.0"