Avoid failing tests on gRPC server shutdown errors

[ashwanthgoli]

What this PR does / why we need it:
TestGRPCGetCacheGenNumbers & TestGRPCGetDeleteRequests keep failing with the following error at line require.NoError(t, baseServer.Serve(lis)) when we shutdown the gRPC server.

Fail in goroutine after TestGRPCGetCacheGenNumbers/error_getting_from_store has completed
...
github.com/stretchr/testify/require.NoError({0x1640260, 0xc000a10340}, {0x16398e0, 0xc000935ef0}, {0x0, 0x0, 0x0})

	/src/loki/vendor/github.com/stretchr/testify/require/require.go:1261 +0x96

github.com/grafana/loki/pkg/storage/stores/indexshipper/compactor/deletion.server.func3()

	/src/loki/pkg/storage/stores/indexshipper/compactor/deletion/grpc_request_handler_test.go:36 +0x50

created by github.com/grafana/loki/pkg/storage/stores/indexshipper/compactor/deletion.server

	/src/loki/pkg/storage/stores/indexshipper/compactor/deletion/grpc_request_handler_test.go:35 +0x2dc

FAIL	github.com/grafana/loki/pkg/storage/stores/indexshipper/compactor/deletion	0.579s

This pr replicates the changes from #6191 to avoid failing the test case on gRPC teardown errors.

replicates the changes
Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide
• Documentation added
• Tests updated
• CHANGELOG.md updated
• Changes that require user attention or interaction to upgrade are documented in docs/sources/upgrading/_index.md

[grafanabot]

./tools/diff_coverage.sh ../loki-target-branch/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki

Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell.

+           ingester	0%
+        distributor	0%
+            querier	0%
+ querier/queryrange	0%
+               iter	0%
+            storage	0%
+           chunkenc	0%
+              logql	0%
+               loki	0%

[dannykopping]

LGTM!

[ssncferreira]

LGTM 👍