Remove deprecated --etcd-quorum-read flag

[liggitt]

What this PR does / why we need it:
Removes the deprecated --etcd-quorum-read flag. This flag was defaulted to true (#53717) and deprecated in 1.9 (#53795).

Setting it to false causes bugs in controllers because of stale reads.

Those bugs can lead to runaway controllers (creating too many objects), stuck controllers (not acting on latest state), and controllers breaking invariants (reacting to objects in different parts of their lifecycle than they are actually in).

Quorum reads performed badly on etcd2, which was the only reason this flag was not removed sooner, but perform well on etcd3. Etcd2 support is dropped in 1.13 in #69310

Special notes for your reviewer:

Release note:

kube-apiserver: the deprecated `--etcd-quorum-read` flag has been removed, and quorum reads are always enabled when fetching data from etcd.

@kubernetes/sig-api-machinery-pr-reviews

[liggitt]

/milestone v1.13

[deads2k]

/lgtm

[k8s-ci-robot]

New changes are detected. LGTM label has been removed.

[liggitt]

fixed up gofmt for 1.11, fixed up unit test store construction, retagging

[fejta-bot]

/retest
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[k8s-ci-robot]

New changes are detected. LGTM label has been removed.

[liggitt]

third time's the charm, removed reference from one more unit test

[spiffxp]

ref: kubernetes/enhancements#622 for the etcd2 drop

[fejta-bot]

/retest
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[spiffxp]

/lgtm cancel
To stop fejta-bot from spamming, this is a failure, not a flake

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: liggitt

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[liggitt]

ok, ok. fourth time was the charm. so many unit tests.