[Rust] [DataFusion] Dockerfile for CLI is missing format dir

[asfimport]

error: failed to run custom build command for `arrow-flight v1.0.0-SNAPSHOT (/arrow/rust/arrow-flight)`Caused by:
  process didn't exit successfully: `/arrow/rust/target/release/build/arrow-flight-a0fb14daffea70f5/build-script-build` (exit code: 1)
--- stderr
Error: Custom { kind: Other, error: "protoc failed: ../../format: warning: directory does not exist.\nCould not make proto path relative: ../../format/Flight.proto: No such file or directory\n" }warning: build failed, waiting for other jobs to finish...
error: failed to compile `datafusion v1.0.0-SNAPSHOT (/arrow/rust/datafusion)`, intermediate artifacts can be found at `/arrow/rust/target`Caused by:
  build failed
 

Reporter: Andy Grove / @andygrove
Assignee: Andy Grove / @andygrove

PRs and other links:

• GitHub Pull Request #6860

_{Note: This issue was originally created as ARROW-8357. Please see the migration documentation for further details.}

[asfimport]

Andy Grove / @andygrove:
Issue resolved by pull request 6860
#6860