chore: Update thanos version to latest main

[yeya24]

What this PR does:
Update Thanos version to latest main branch. To do this I changed the go module go version from 1.16 to 1.18.

Notable changes:

• Compact: Make GatherNoCompactionMarkFilter.NoCompactMarkedBlocks concurrency safe thanos-io/thanos#5736
• Remove hardcoded labels in store shard matcher and inject unshardable label in query analyzer thanos-io/thanos#5641
• add metrics for bucket store empty postings count thanos-io/thanos#5721
• block fetcher: hide TxGaugeVec behind an interface thanos-io/thanos#5640
• Store: improve index header reading performance by sorting values thanos-io/thanos#5588

Also https://github.com/thanos-io/objstore has been updated to the latest version as well, which means we can support OCI object storage.

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[alanprot]

Thanks!! LGTM!

[yeya24]

I guess it is a flake, let me retry.

--- FAIL: TestCompactor_ShouldCompactOnlyShardsOwnedByTheInstanceOnShardingEnabledWithShuffleShardingAndMultipleInstancesRunning (4.74s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x16a1a09]

goroutine 1124 [running]:
testing.tRunner.func1.2({0x1b602c0, 0x[35](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:36)faec0})
	/usr/local/go/src/testing/testing.go:1396 +0x[37](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:38)2
testing.tRunner.func1()
	/usr/local/go/src/testing/testing.go:1[39](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:40)9 +0x5f0
panic({0x1b602c0, 0x35faec0})
	/usr/local/go/src/runtime/panic.go:890 +0x262
github.com/cortexproject/cortex/pkg/util/concurrency.(*SyncBuffer).String(0x0)
	/__w/cortex/cortex/pkg/util/concurrency/buffer.go:22 +0x49
github.com/cortexproject/cortex/pkg/compactor.TestCompactor_ShouldCompactOnlyShardsOwnedByTheInstanceOnShardingEnabledWithShuffleShardingAndMultipleInstancesRunning(0xc01c8[42](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:43)000)
	/__w/cortex/cortex/pkg/compactor/compactor_test.go:1298 +0x1528
testing.tRunner(0xc01c842000, 0x1dcc280)
	/usr/local/go/src/testing/testing.go:1[44](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:45)6 +0x217
created by testing.(*T).Run
	/usr/local/go/src/testing/testing.go:1[49](https://github.com/cortexproject/cortex/actions/runs/3147946878/jobs/5117963435#step:5:50)3 +0x75e