chore(go): weekly Go toolchain upgrade

[localstack-bot]

Automated weekly Go toolchain upgrade.

• Updates the toolchain directive to the latest released Go version.
• Runs go mod tidy to keep module files consistent.

[claude]

This is the automated weekly Go toolchain bump (go1.26.6 → go1.27.0) in both go.mod files; the change itself is minimal and consistent, but it currently reddens CI.

1. issue(blocking): The Lint job fails on this head — golangci-lint v2.9.0 (pinned in .tool-versions, built with go1.26) refuses to run against the now-targeted go1.27.0: can't load config: the Go language version (go1.26) used to build golangci-lint is lower than the targeted Go version (1.27.0). The toolchain bump needs a matching golangci-lint bump in .tool-versions (to a release built with Go ≥1.27) in the same PR before this can merge.
2. thought: This breakage recurs whenever Go's toolchain outpaces the pinned linter — consider having weekly-go-upgrade.yml also bump golangci-lint to latest in the generated PR so the linter and toolchain stay in lockstep.

Automated review on behalf of @gtsiolis.

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Generated by Claude Code

[claude]

Re-review of the re-pushed weekly toolchain bump (go1.26.6 → go1.27.0); the change is still minimal and consistent, but the blocking lint breakage I flagged before is unresolved on this new commit.

1. issue(blocking): .tool-versions still pins golangci-lint 2.9.0 (built with go1.26), so the Lint job stays red on this head while every other job is green — I confirmed via the check-runs API that Lint failed with golangci-lint exit code 3 (config load). Bump golangci-lint to a release built with Go ≥1.27 in this same PR so the linter can target go1.27.0.
2. thought(non-blocking): as noted last time, having weekly-go-upgrade.yml also bump golangci-lint to latest in the generated PR would keep linter and toolchain in lockstep and stop this recurring weekly.

Automated review on behalf of @gtsiolis.

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Generated by Claude Code