ARROW-11317: [Rust] Include the prettyprint feature in CI Coverage

This PR changes the Rust CI job to include the prettyprint feature. (so we have CI coverage of that feature)

As @paddyhoran  noted, passing in feature flags to the root workspace doesn't do anything, and as it turns out we already invoke `cargo test` for the `arrow` crate separately. Prior to this PR I think that just ran the same tests again with the same features. After this PR, the second run of the arrow tests are run with the `prettyprint` feature

Here is evidence that the tests are running twice. I picked a PR (randomly)
https://github.com/apache/arrow/pull/9258/checks?check_run_id=1725967358

If you look at the logs for the run-tests action
![Screen Shot 2021-01-19 at 7 42 13 AM](https://user-images.githubusercontent.com/490673/105036642-c4188680-5a2a-11eb-8968-c570d855724e.png)

You can see that the same test is run twice:

```
2021-01-19T07:02:49.9476111Z test compute::kernels::boolean::tests::test_nonnull_array_is_not_null ... ok
2021-01-19T07:02:49.9476854Z test compute::kernels::boolean::tests::test_nonnull_array_is_null ... ok
2021-01-19T07:02:49.9477616Z test compute::kernels::boolean::tests::test_nonnull_array_with_offset_is_not_null ... ok
2021-01-19T07:02:49.9478427Z test compute::kernels::boolean::tests::test_nonnull_array_with_offset_is_null ... ok
2021-01-19T07:02:49.9479207Z test compute::kernels::boolean::tests::test_nullable_array_is_null ... ok
2021-01-19T07:02:49.9479948Z test compute::kernels::boolean::tests::test_nullable_array_is_not_null ... ok
2021-01-19T07:02:49.9480744Z test compute::kernels::boolean::tests::test_nullable_array_with_offset_is_not_null ... ok
2021-01-19T07:02:49.9481640Z test compute::kernels::boolean::tests::test_nullable_array_with_offset_is_null ... ok
2021-01-19T07:02:49.9487019Z test compute::kernels::boolean::tests::test_nullif_int_array_offset ... ok
2021-01-19T07:02:49.9487773Z test compute::kernels::boolean::tests::test_nullif_int_array ... ok
...
2021-01-19T07:07:23.4568865Z test compute::kernels::boolean::tests::test_nonnull_array_is_not_null ... ok
2021-01-19T07:07:23.4569576Z test compute::kernels::boolean::tests::test_nonnull_array_is_null ... ok
2021-01-19T07:07:23.4570337Z test compute::kernels::boolean::tests::test_nonnull_array_with_offset_is_not_null ... ok
2021-01-19T07:07:23.4571133Z test compute::kernels::boolean::tests::test_nonnull_array_with_offset_is_null ... ok
2021-01-19T07:07:23.4571885Z test compute::kernels::boolean::tests::test_nullable_array_is_not_null ... ok
2021-01-19T07:07:23.4572614Z test compute::kernels::boolean::tests::test_nullable_array_is_null ... ok
2021-01-19T07:07:23.4573383Z test compute::kernels::boolean::tests::test_nullable_array_with_offset_is_not_null ... ok
2021-01-19T07:07:23.4574183Z test compute::kernels::boolean::tests::test_nullable_array_with_offset_is_null ... ok
2021-01-19T07:07:23.4574929Z test compute::kernels::boolean::tests::test_nullif_int_array ... ok
2021-01-19T07:07:23.4575636Z test compute::kernels::boolean::tests::test_nullif_int_array_offset ... ok
```

Closes apache#9262 from alamb/alamb/run_prettyprint_ci

Authored-by: Andrew Lamb <andrew@nerdnetworks.org>
Signed-off-by: Jorge C. Leitao <jorgecarleitao@gmail.com>

.github/workflows/rust.yml

@@ -109,14 +109,16 @@ jobs:
           export CARGO_HOME="/github/home/.cargo"
           export CARGO_TARGET_DIR="/github/home/target"
           cd rust
+          # run tests on all workspace members with default feature list
           cargo test
           # test datafusion examples
           cd datafusion
           cargo run --example csv_sql
           cargo run --example parquet_sql
           cd ..
           cd arrow
-          cargo test
+          # re-run tests on arrow workspace with additional features
+          cargo test --features=prettyprint
           cargo run --example builders
           cargo run --example dynamic_types
           cargo run --example read_csv