ci: stop the Go lint step verifying its config over the network

[otavio]

golangci-lint-action defaults to verify: true, which runs golangci-lint config verify before
linting. That command fetches its JSON schema from golangci-lint.run and has no offline mode —
there is no --schema flag, and a $schema key in the config is rejected as an unknown property.

So every push made four requests to a third-party host, one per matrix leg, on the path that gates
merges. On run 33672076496 one
timed out and QA went red on master:

##[error]Failed to run: Error: Command failed: golangci-lint config verify
  [../.golangci.yaml] validate: compile schema: failing loading
  "https://golangci-lint.run/jsonschema/golangci.v2.11.jsonschema.json":
  context deadline exceeded (Client.Timeout exceeded while awaiting headers)

The linter never ran. No .go file was analysed.

What this gives up

Tested against the real .golangci.yaml with v2.11.3:

Broken config	golangci-lint run	config verify
Unknown linter name	exit 3, can't load config	catches
YAML syntax / type error	exit 3, can't read viper config	catches
Unknown top-level key (linterz:)	exit 1, silently ignored	exit 3, additional properties not allowed

Only the third row is lost. run aborts on the other two by itself, so those stay covered.

The gap is real: viper ignores keys it does not recognise, so a misspelled block reads as
configuration and configures nothing. It is accepted because the config changes rarely, a typo in
it is not urgent, and the alternative was letting an external host decide whether master is green.

If the gap starts to matter, the fix is a scheduled job running config verify on its own — off
the merge path, where an outage costs nothing.

[github-actions]

Claude finished @otavio's task in 20s —— View job

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Code Review Complete

Reviewed 1 file across code quality, security, testing, language patterns, and architecture — no new issues found. The code looks good as-is.

verify: false is a valid input for golangci-lint-action v9, and the change correctly removes the network dependency (golangci-lint config verify fetching its JSON schema from golangci-lint.run) that was gating merges. The PR body clearly documents the one capability given up — unknown top-level keys silently ignored by viper — and the reasoning holds: golangci-lint run still aborts on unknown linter names and YAML/type errors on its own.

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