[MINOR][MAINTENANCE] Sort the entries in .gitignore.

## What changes were proposed in this pull request?

The contents of `.gitignore` have been sorted to make it more readable. The actual contents of the file have not been changed.

## How was this patch tested?

Does not require any tests.

Author: Arun Allamsetty <arun@instructure.com>

Closes #12742 from aa8y/gitignore.

.gitignore

@@ -1,78 +1,78 @@
-*~
-*.#*
 *#*#
-*.swp
-*.ipr
+*.#*
 *.iml
+*.ipr
 *.iws
 *.pyc
 *.pyo
-.idea/
-.idea_modules/
-build/*.jar
-.settings
-.cache
-cache
-.generated-mima*
-work/
-out/
+*.swp
+*~
 .DS_Store
-build/apache-maven*
-build/zinc*
-build/scala*
-scalastyle-on-compile.generated.xml
-conf/java-opts
-conf/*.sh
-conf/*.cmd
-conf/*.properties
-conf/*.conf
-conf/*.xml
-conf/slaves
-docs/_site
-docs/api
-target/
-reports/
-.project
+.cache
 .classpath
-.scala_dependencies
-lib_managed/
-src_managed/
-project/boot/
-project/plugins/project/build.properties
-project/build/target/
-project/plugins/target/
-project/plugins/lib_managed/
-project/plugins/src_managed/
-logs/
-log/
-spark-tests.log
-streaming-tests.log
-dependency-reduced-pom.xml
 .ensime
 .ensime_cache/
 .ensime_lucene
-checkpoint
-derby.log
-dist/
-dev/create-release/*txt
-dev/create-release/*final
-spark-*-bin-*.tgz
-unit-tests.log
+.generated-mima*
+.idea/
+.idea_modules/
+.project
+.scala_dependencies
+.settings
 /lib/
-scalastyle.txt
-scalastyle-output.xml
 R-unit-tests.log
 R/unit-tests.out
-python/lib/pyspark.zip
+build/*.jar
+build/apache-maven*
+build/scala*
+build/zinc*
+cache
+checkpoint
+conf/*.cmd
+conf/*.conf
+conf/*.properties
+conf/*.sh
+conf/*.xml
+conf/java-opts
+conf/slaves
+dependency-reduced-pom.xml
+derby.log
+dev/create-release/*final
+dev/create-release/*txt
+dist/
+docs/_site
+docs/api
+lib_managed/
 lint-r-report.log
+log/
+logs/
+out/
+project/boot/
+project/build/target/
+project/plugins/lib_managed/
+project/plugins/project/build.properties
+project/plugins/src_managed/
+project/plugins/target/
+python/lib/pyspark.zip
+reports/
+scalastyle-on-compile.generated.xml
+scalastyle-output.xml
+scalastyle.txt
+spark-*-bin-*.tgz
+spark-tests.log
+src_managed/
+streaming-tests.log
+target/
+unit-tests.log
+work/
 
 # For Hive
-metastore_db/
-metastore/
-warehouse/
 TempStatsStore/
+metastore/
+metastore_db/
 sql/hive-thriftserver/test_warehouses
+warehouse/
 
 # For R session data
-.RHistory
 .RData
+.RHistory