Upgrade Prometheus

[pracucci]

What this PR does:
As a pre-requisite to continue the work on query sharding we need to upgrade vendored Prometheus, which is what I'm doing in this PR.

Among other things, this include a dependencies upgrade done in Prometheus (commit) so I've checked the changelog / release notes for all update dependencies. See below for more details.

The following dep upgrade LGTM:

• github.com/prometheus/common from v0.29.0 to v0.30.0: Add the ability to enable HTTP2 again via an env variable.
• github.com/aws/aws-sdk-go from v1.38.60 to v1.40.10: checked the CHANGELOG and haven't seen anything relevant to us
• github.com/hashicorp/consul/api from v1.8.1 to v1.9.1: checked the "api" changes in the CHANGELOG and haven't seen any breaking change (only improvements and fixes)
• github.com/golang/snappy from v0.0.3 to v0.0.4. A couple of changes:
  • Add ReadByte method, satisfies the io.ByteReader interface golang/snappy#51
  • Fix wrong arm64 scaled register format golang/snappy#61
• github.com/gorilla/mux from v1.7.3 to v1.8.0: checked the release notes, should be good to us
• github.com/spf13/afero from v1.2.2 to v1.3.4: checked the release notes and haven't seen any breaking changes
• github.com/miekg/dns from v1.1.42 to v1.1.43: looking at the commits diff I can only see some cleanup and few small fixes
• cloud.google.com/go from 0.83.0 to 0.87.0 (+ its deps): checked the CHANGELOG and haven't seen any breaking change.
• google.golang.org/protobuf from v1.26.0 to v1.27.1: checked the release notes and changes should not affect us

On the contrary, I've pinned the following packages to address their upgrade in separate PRs:

• google.golang.org/grpc pinned to v1.38.0, because v1.39.0 has introduced a behaviour change that could impact us or our dependencies

Which issue(s) this PR fixes:
N/A

Checklist

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

[pracucci]

Let me clarify what I'm doing in this PR.

We're upgrading to main that was when we forked into prometheus-private. Then, to avoid having to upgrade Prometheus in Mimir at that time, we referenced the same version of prometheus-private as we had in cortex/master, while now I'm proposing to upgrade to latest commit we had when we forked.

In main we're using our custom fork, but pointing to old commit still. In this PR I'm bumping the commit to latest.