update rat check to exclude stability files

[andygrove]

What is the problem the feature request solves?

I ran into this during the release. I will create a PR soon to fix this.

Running rat license checker on /Users/andy/git/apple/apache-datafusion-comet/dev/dist/apache-datafusion-comet-0.12.0-rc1/apache-datafusion-comet-0.12.0.tar.gz
     810 unapproved licences. Check rat report: rat.txt
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q1.native_iceberg_compat/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q1.native_iceberg_compat/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q1/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q1/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q10.native_iceberg_compat/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q10.native_iceberg_compat/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q10/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q10/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q11.native_iceberg_compat/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q11.native_iceberg_compat/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q11/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q11/extended.txt): false
NOT APPROVED: spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q12.native_iceberg_compat/extended.txt (apache-datafusion-comet-0.12.0/spark/src/test/resources/tpcds-plan-stability/approved-plans-v1_4-spark3_5/q12.native_iceberg_compat/extended.txt): false
...

Describe the potential solution

No response

Additional context

No response