Bump github.com/attestantio/go-eth2-client from 0.19.10 to 0.21.11

[dependabot]

Bumps github.com/attestantio/go-eth2-client from 0.19.10 to 0.21.11.

Changelog

Sourced from github.com/attestantio/go-eth2-client's changelog.

dev:

• add attester_slashing, block_gossip, bls_to_execution_change and proposer_slashing events

0.21.10:

• better validator state when balance not supplied

0.21.9:

• enable custom timeouts for POSTs

0.21.8:

• remove Lodestar proposals workaround
• add client headers for events stream

0.21.7:

• use POST for specific validator and validator balance information

0.21.6:

• use SSZ on a per-call basis

0.21.5:

• ensure POST bodies are logged as JSON

0.21.4:

• additional nil checks
• allow non-mainnet configurations

0.21.3:

• relax requirement for proposals to use the graffiti we request

0.21.2:

• fuzz testing fixes

0.21.1:

• fix potential crash when unmarshaling Gwei values
• add WithReducedMemoryUsage() option for http service
• more consistent tracing attributes and codes

0.21.0:

• use v3 of the endpoint to obtain proposals
• add bounds checking for ValidatorState

0.20.0:

• allow delayed start of client, enabling the service even if the underlying beacon node is not ready
• add IsActive() and IsSynced() methods to understand the status of the service
• update multi clients to be aware of delayed start, only using clients that are synced
• use standard errors for common function issues
• add ProposerIndex() to VersionedSignedProposal
• add name to multi clients to differentiate multiple instances
• fully parse provided client URLs, allowing pass through of username, password, etc.

Commits

• 50179b8 Tidy-ups.
• d9f7691 Update test.
• 5608aaa Allow filtering of attestationpool by committee index.
• 490d07a Add events.
• b3d8c14 Better handling of validator state when no balance is present.
• f925432 Better handling of empty responses.
• 633b784 Formatting.
• 512fdce Bump version.
• 2450464 Enable per-request timeout for POSTs.
• 22abb36 Enable per-request timeout for POSTs.
• Additional commits viewable in compare view

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[dependabot]

Dependabot tried to add @metachris as a reviewer to this PR, but received the following error from GitHub:

POST https://api.github.com/repos/chainbound/bolt-mev-boost/pulls/4/requested_reviewers: 422 - Reviews may only be requested from collaborators. One or more of the users or teams you specified is not a collaborator of the chainbound/bolt-mev-boost repository. // See: https://docs.github.com/rest/pulls/review-requests#request-reviewers-for-a-pull-request

[dependabot]

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