[MINOR] Add .crc files to .gitignore

## What changes were proposed in this pull request?

Add .crc files to .gitignore so that we don't add .crc files in state checkpoint to git repo which could be added in test resources.
This is based on comments in apache#21733, apache#21733 (comment).

## How was this patch tested?

Add `.1.delta.crc` and `.2.delta.crc` in `<spark root>/sql/core/src/test/resources`, and confirm git doesn't suggest the files to add to stage.

Closes apache#22170 from HeartSaVioR/add-crc-files-to-gitignore.

Authored-by: Jungtaek Lim <[email protected]>
Signed-off-by: hyukjinkwon <[email protected]>

.gitignore

@@ -77,6 +77,7 @@ target/
 unit-tests.log
 work/
 docs/.jekyll-metadata
+*.crc
 
 # For Hive
 TempStatsStore/