chore: E2E tests for built-in Pulsar source

[BulkBeing]

Explain what this PR does.

Closes #2254

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 64.92%. Comparing base (05df886) to head (cd54c7b).
Report is 19 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2260      +/-   ##
==========================================
+ Coverage   64.75%   64.92%   +0.17%     
==========================================
  Files         345      345              
  Lines       41415    41465      +50     
==========================================
+ Hits        26819    26922     +103     
+ Misses      13528    13470      -58     
- Partials     1068     1073       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[KeranYang]

Please consider adding it to the builtin-source-e2e suite instead of creating a new one. Otherwise, you need to add it to the .github/workflows/ci.yaml

[BulkBeing]

Please consider adding it to the builtin-source-e2e suite instead of creating a new one. Otherwise, you need to add it to the .github/workflows/ci.yaml

I've added it to ci.yaml instead of making it part of the builtin-source-e2e suite since we will be implementing the Pulsar sink in the future.

[BulkBeing]

Snyk reports vulnerabilities with 2 indirect dependencies that got added when I added http://github.com/apache/pulsar-client-go (latest version).

• http://github.com/hamba/avro
• http://github.com/AthenZ/athenz (issue is with its transitive dependencies)

I tried upgrading these indirect dependencies, but then all other tests started failing https://github.com/numaproj/numaflow/actions/runs/12193339406

    udsource_test.go:127: 
        	Error Trace:	/home/runner/work/numaflow/numaflow/test/udsource-e2e/udsource_test.go:127
        	            				/opt/hostedtoolcache/go/1.23.3/x64/src/runtime/asm_amd64.s:1700
        	Error:      	Received unexpected error:
        	            	rpc error: code = Unavailable desc = connection error: desc = "transport: authentication handshake failed: credentials: cannot check peer: missing selected ALPN property"
        	Test:       	TestUserDefinedSourceSuite/TestUDSource
panic: runtime error: index out of range [0] with length 0

[vigith]

@BulkBeing please add the CI