[FIX] Update dependencies

[bbengfort]

Scope of changes

Updates dependencies and appeases linter and tests.

Type of change

• bug fix
• new feature
• documentation
• other (describe)

Acceptance criteria

This PR will be merged without review.

Author checklist

• I have manually tested the change and/or added automation in the form of unit tests or integration tests
• I have updated the dependencies list
• I have recompiled and included new protocol buffers to reflect changes I made
• I have added new test fixtures as needed to support added tests

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Note

Medium Risk
Medium risk due to the Go toolchain jump to 1.26 and broad dependency upgrades, which can introduce subtle build/runtime changes and regenerated protobuf output. Workflow action version bumps are low risk but could affect CI/container builds if compatibility issues arise.

Overview
Upgrades the codebase to Go 1.26.x (module go 1.26.1, CI, and container builder images) and bumps staticcheck plus a broad set of Go module dependencies (e.g. gin, grpc, google.golang.org/api, sentry, auth0, prometheus, trisa).

Regenerates protobuf outputs (pkg/bff/models/v1/models.pb.go, pkg/gds/admin/v1/*.pb.go) with newer protoc/generators (notably switching raw descriptor handling to unsafe string slicing), updates GitHub Actions checkouts to actions/checkout@v6, and adjusts admin tests to expect the updated review-note author email (admin@trisa.io).

^{Reviewed by Cursor Bugbot for commit 15f6d74. Configure here.}

[bbengfort]

This email addresses are in the fixtures … since we're going to be doing GDS 2.0 soon I figured there wasn't a point in changing the fixtures which is actually a lot of work.