pin lib versions for older python versions

Author: abbrowne126

samples/snippets/requirements-test.txt

@@ -3,6 +3,6 @@ pytest===7.4.4; python_version == '3.7'
 pytest==8.4.0; python_version >= '3.8'
 mock==5.2.0
 flaky==3.8.1
-google-cloud-bigquery==3.34.0; python_version < '3.9'
+google-cloud-bigquery===3.30.0; python_version < '3.9'
 google-cloud-bigquery==3.34.0; python_version >= '3.9'
 google-cloud-storage==3.1.0

samples/snippets/requirements.txt

@@ -6,6 +6,6 @@ protobuf==6.31.1; python_version >= '3.9'
 avro==1.12.0
 opentelemetry-api===1.22.0; python_version == '3.7'
 opentelemetry-sdk===1.22.0; python_version == '3.7'
-opentelemetry-api==1.34.1; python_version >= '3.8'
+opentelemetry-api===1.33.1; python_version >= '3.8'
 opentelemetry-sdk==1.34.1; python_version >= '3.8'
 opentelemetry-exporter-gcp-trace==1.9.0