Bump google.golang.org/grpc from 1.65.0 to 1.68.0 #9747

Job	Run time
Build	1m 42s
Run Unit Tests (test-with-cover-pkg)	3m 1s
Build technical documentation	20s
Run Unit Tests (test-with-cover-tempodb)	3m 15s
Benchmark	9m 22s
Run integration tests (test-e2e)	28m 15s
Run Unit Tests (test-with-cover-tempodb-wal)	3m 15s
Run integration tests (test-integration-poller)	9m 47s
Lint	3m 13s
Run Unit Tests (test-with-cover-others)	3m 15s
Check jsonnet & tempo-mixin	46s
Run integration tests (test-e2e-deployments)	13m 20s
Run integration tests (test-e2e-serverless)	7m 6s
Vendor check	1m 16s
	1h 27m 53s

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