fix(nodejs): bundle missing winston-transport dependency in Lambda layer

[pujitha24]

Motivation:
Enabling winston via OTEL_NODE_ENABLED_INSTRUMENTATIONS never exported
winston logs to the configured OTLP backend. The layer's webpack build
already emitted "Module not found: Error: Can't resolve
'@opentelemetry/winston-transport'" for the require inside
@opentelemetry/instrumentation-winston's patched configure(), which
attaches an OpenTelemetryTransportV3 transport to export logs. Since
@opentelemetry/winston-transport was declared as neither a dependency of
@opentelemetry/instrumentation-winston nor of this layer's package.json,
it was never bundled, the require always threw MODULE_NOT_FOUND inside a
caught try/catch, and the transport (and therefore log export) was
silently skipped. Log correlation (trace_id/span_id injection into log
records via the patched write/log methods) is a separate code path and
is unaffected by this bug.

This does not confirm the race condition theorized in the report (async
LoggerProvider creation racing synchronous instrumentation registration
in wrapper.ts) - init.mjs awaits both wrapper.init() and wrapper.wrap()
to completion, including LoggerProvider creation, before the Lambda
handler module is ever loaded, so the LoggerProvider is already set by
the time user code creates a winston logger.

Approach:
Add @opentelemetry/winston-transport to the layer's dependencies so it
is bundled by webpack alongside the other auto-instrumentation packages.
Add winston as a devDependency to exercise the real auto-instrumentation
path in a new regression test.

Validation:

• npm run compile:webpack in nodejs/packages/layer: before this change,
  printed a "Module not found" warning for '@opentelemetry/winston-transport';
  after, compiles cleanly with winston-transport bundled.
• npm run build in nodejs/packages/layer: full build (webpack, externals
  install, packaging) succeeds and produces layer.zip.
• Added nodejs/packages/layer/test/winston-instrumentation.spec.ts, which
  enables WinstonInstrumentation, requires winston, creates a logger, and
  asserts an OpenTelemetryTransportV3 transport gets attached. Verified this
  test fails with an assertion error when @opentelemetry/winston-transport
  is removed from node_modules (reproducing the reported symptom), and
  passes with the dependency present.
• npm test in nodejs/packages/layer (test:cjs + test:esm): 16/16 passing,
  no regressions in existing wrapper/handler tests.
• npm run lint in nodejs/packages/layer: clean.

Report: #2065
Signed-off-by: Pujitha Paladugu 10557236+pujitha24@users.noreply.github.com

Fixes #2065