Stop using invalid escape sequences (#9073)

Fixes #8980 

Replace strings with invalid escape sequences with the equivalent raw literals 

## Testing

```bash
$ ./integration_tests/run_pyspark_from_build.sh -k 'regexp_test or get_json_test' |& tee build.log
$ grep -c 'invalid escape' build.log 
0
```

Signed-off-by: Gera Shegalov <gera@apache.org>

integration_tests/src/main/python/get_json_test.py

@@ -47,7 +47,7 @@ def test_get_json_object(json_str_pattern):
 def test_unsupported_fallback_get_json_object(json_str_pattern):
     gen = mk_json_str_gen(json_str_pattern)
     scalar_json = '{"store": {"fruit": "test"}}'
-    pattern = StringGen(pattern='\$\.[a-z]{1,9}')
+    pattern = StringGen(pattern=r'\$\.[a-z]{1,9}')
     def assert_gpu_did_fallback(sql_text):
         assert_gpu_fallback_collect(lambda spark:
             gen_df(spark, [('a', gen), ('b', pattern)], length=10).selectExpr(sql_text),

integration_tests/src/main/python/regexp_test.py

@@ -12,11 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import locale
 import pytest
 
 from asserts import assert_gpu_and_cpu_are_equal_collect, assert_gpu_fallback_collect, \
-    assert_cpu_and_gpu_are_equal_collect_with_capture, assert_gpu_and_cpu_error, \
+    assert_gpu_and_cpu_error, \
     assert_gpu_sql_fallback_collect
 from data_gen import *
 from marks import *
@@ -520,7 +519,7 @@ def test_word_boundaries():
                 'regexp_replace(a, "\\\\B", "#")',
             ),
         conf=_regexp_conf)
-        
+
 def test_character_classes():
     gen = mk_str_gen('[abcd]{1,3}[0-9]{1,3}[abcd]{1,3}[ \n\t\r]{0,2}')
     assert_gpu_and_cpu_are_equal_collect(
@@ -864,7 +863,7 @@ def test_regexp_replace_fallback_configured_off():
 @allow_non_gpu('ProjectExec')
 def test_unsupported_fallback_regexp_extract():
     gen = mk_str_gen('[abcdef]{0,2}')
-    regex_gen = StringGen('\[a-z\]\+')
+    regex_gen = StringGen(r'\[a-z\]\+')
     num_gen = IntegerGen(min_val=0, max_val=0, special_cases=[])
 
     def assert_gpu_did_fallback(sql_text):
@@ -886,7 +885,7 @@ def assert_gpu_did_fallback(sql_text):
 @allow_non_gpu('ProjectExec')
 def test_unsupported_fallback_regexp_extract_all():
     gen = mk_str_gen('[abcdef]{0,2}')
-    regex_gen = StringGen('\[a-z\]\+')
+    regex_gen = StringGen(r'\[a-z\]\+')
     num_gen = IntegerGen(min_val=0, max_val=0, special_cases=[])
     def assert_gpu_did_fallback(sql_text):
         assert_gpu_fallback_collect(lambda spark:
@@ -907,7 +906,7 @@ def assert_gpu_did_fallback(sql_text):
 @allow_non_gpu('ProjectExec', 'RegExpReplace')
 def test_unsupported_fallback_regexp_replace():
     gen = mk_str_gen('[abcdef]{0,2}')
-    regex_gen = StringGen('\[a-z\]\+')
+    regex_gen = StringGen(r'\[a-z\]\+')
     def assert_gpu_did_fallback(sql_text):
         assert_gpu_fallback_collect(lambda spark:
             gen_df(spark, [
@@ -992,7 +991,7 @@ def test_regexp_memory_fallback():
             'a rlike "1|2|3|4|5|6"'
         ),
         cpu_fallback_class_name='RLike',
-        conf={ 
+        conf={
             'spark.rapids.sql.regexp.enabled': True,
             'spark.rapids.sql.regexp.maxStateMemoryBytes': '10',
             'spark.rapids.sql.batchSizeBytes': '20' # 1 row in the batch
@@ -1014,7 +1013,7 @@ def test_regexp_memory_ok():
             'a rlike "(1)(2)(3)"',
             'a rlike "1|2|3|4|5|6"'
         ),
-        conf={ 
+        conf={
             'spark.rapids.sql.regexp.enabled': True,
             'spark.rapids.sql.regexp.maxStateMemoryBytes': '12',
             'spark.rapids.sql.batchSizeBytes': '20' # 1 row in the batch