Update dependency google-cloud-core to v1.7.3

Author: renovate[bot]

requirements.txt

@@ -6,7 +6,7 @@ future==0.18.2
 google-api-core==1.22.1
 google-auth==1.21.0
 google-cloud-bigquery==1.27.2
-google-cloud-core==1.4.1
+google-cloud-core==1.7.3
 google-crc32c==1.0.0
 google-resumable-media==1.0.0
 googleapis-common-protos==1.52.0