fix: tests, ci failures, minor dep updates

[mrz1836]

This pull request introduces several dependency updates, improvements to server-sent events (SSE) handling, and minor codebase cleanups. The most significant changes are grouped below:

Dependency Updates:

• Upgraded many dependencies in go.mod to their latest versions, including major libraries such as github.com/IBM/sarama, github.com/aerospike/aerospike-client-go/v7, github.com/bsv-blockchain/teranode, github.com/gin-gonic/gin, go.uber.org/zap, and various indirect dependencies. These updates improve security, performance, and compatibility. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]

SSE (Server-Sent Events) Handling Improvements:

• Added a closed flag and close() method to the sseWriter struct to ensure that no writes occur after the HTTP response is being finalized, preventing potential race conditions and panics.
• Updated SSE stream handlers (handleTipStream and handleReorgStream) to call writer.close() when a client disconnects, ensuring proper cleanup. [1] [2]
• Enhanced the sseStoreStub used in tests with mutex protection for its fixtures, ensuring thread-safety and avoiding race conditions during concurrent access.

Testing and Code Quality:

• Refactored test harness code to use a thread-safe setStatus method for updating transaction statuses, improving reliability of SSE E2E tests.
• Improved documentation and code comments for clarity, especially around concurrency and mutation safety in tests and core functions. [1] [2]

Benchmark and Test Infrastructure:

• Simplified and stabilized the Postgres benchmark setup by reusing a shared store and skipping tests if unavailable, reducing setup time and flakiness.

Function Return Value Correction:

• Fixed the return value of multiSubtreeTestSetup to return all expected results, improving test correctness.