test: stabilize formatting and live RPC fixtures

[aivarasko]

Changes

• Apply gofumpt v0.9.2 formatting to the E2E key tests and generated script cleanup.
• Pin gofumpt and abigen to the versions used when PR chore: merge v1.11.1 in develop #546 passed.
• Resolve generated-file and format-check drift caused by unpinned latest tools.
• Replace the Hoodi Tatum RPC endpoint with the public ethPandaOps endpoint to avoid paid-plan eth_call failures.
• Replace the unreliable Mainnet LlamaRPC test endpoint with the existing keyless PublicNode endpoint.
• Refresh the static Mainnet relay fixture to match the current on-chain MEV-Boost allowed list.

Types of changes

• Bugfix (non-breaking change)
• New feature (non-breaking change)
• Breaking change
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other

Testing

• Yes
• No new tests required; this change updates formatting, tool version pins, and live RPC test fixtures.

Validation completed:

• gofumpt v0.9.2 -l .
• make generate with abigen v1.16.8
• make format-check
• go test ./configs ./internal/pkg/clients ./internal/pkg/generate
• go test ./e2e/sedge -run '^$'
• Focused Hoodi contract connection tests
• Focused Mainnet contract connection test
• go test ./e2e/lido-exporter -run '^TestE2E_Valid(Env|Flags)_All_Mainnet$'
• Focused Mainnet relay-list comparison against the on-chain contract

The relay-list test uses live on-chain data and may be affected by transient public RPC timeouts.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 24.47%. Comparing base (ae12d83) to head (361f051).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #551   +/-   ##
========================================
  Coverage    24.47%   24.47%           
========================================
  Files          122      122           
  Lines        20110    20110           
========================================
  Hits          4921     4921           
  Misses       14601    14601           
  Partials       588      588           

Flag	Coverage Δ
unittests	24.47% <100.00%> (ø)

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