fix(detector-aws): remove semconv incubating import

[garysassano]

Which problem is this PR solving?

The AWS detectors are directly importing experimental attributes from @opentelemetry/semantic-conventions/incubating, which can lead to breaking changes in minor versions and increased disk usage due to having multiple package versions installed.

Short description of the changes

• Created a shared /src/semconv.ts file with generated unstable semantic conventions
• Updated imports in AWS detectors to use the local /src/semconv.ts file

This follows the OpenTelemetry best practices for handling unstable semantic conventions.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.84%. Comparing base (4fb610d) to head (0ac7ca1).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2668      +/-   ##
==========================================
+ Coverage   90.80%   90.84%   +0.03%     
==========================================
  Files         170      171       +1     
  Lines        8070     8102      +32     
  Branches     1646     1646              
==========================================
+ Hits         7328     7360      +32     
  Misses        742      742              

Files with missing lines	Coverage Δ
...ctor-aws/src/detectors/AwsBeanstalkDetectorSync.ts	96.55% <100.00%> (+0.12%)	⬆️
...e-detector-aws/src/detectors/AwsEc2DetectorSync.ts	98.21% <ø> (ø)
...e-detector-aws/src/detectors/AwsEcsDetectorSync.ts	97.11% <100.00%> (ø)
...e-detector-aws/src/detectors/AwsEksDetectorSync.ts	91.86% <ø> (ø)
...etector-aws/src/detectors/AwsLambdaDetectorSync.ts	100.00% <ø> (ø)
...opentelemetry-resource-detector-aws/src/semconv.ts	100.00% <100.00%> (ø)

[trentm]

@garysassano Thanks. Heads up that I pushed a couple of commits to your feature branch. Happy to discuss the changes:

• I moved src/lib/semconv.ts to src/semconv.ts. I don't see the value of the "lib/" subdir. Other packages will be using "src/semconv.ts" (e.g. instrumentation-pg already does).
• I added the block comments for the copied vars: these are helpful for tooltips and deprecated styling in some IDEs. I've scripted the generation of semconv.ts (see chore: add scripts/gen-semconv-ts.js to help generate semconv.ts files for unstable semconv consts #2669 for the PR adding the generator script).
• I moved two of the imports that are stable to import directly from @opentelemetry/semantic-conventions. The generator script warns about these cases.

[garysassano]

I moved src/lib/semconv.ts to src/semconv.ts. I don't see the value of the "lib/" subdir. Other packages will be using "src/semconv.ts" (e.g. instrumentation-pg already does).

I would have preferred using /lib/semconv.ts instead of /src/semconv.ts to allow imports from /tests as ../lib/semconv rather than ../src/semconv.ts. However, I noticed that the NX build fails unless everything is within the /src folder, so I'm fine with your changes.