fix(examples): align otel-collector builder-config with v0.151.0 release line

[hitkall]

Description

The examples/otel-collector example fails to build because the component versions in examples/otel-collector/builder-config.yaml have drifted out of sync with the Collector release line OBI itself depends on. The config pinned components to the v0.145.0 / v1.51.0 line, while the repo's root go.mod is on v0.151.0 (stable modules at v1.57.0). Building with a current ocb fails with undefined symbols in xexporterhelper.

This PR realigns every component to the v0.151.0 release line (matching go.mod), without changing which components are included.

Changes

• builder-config.yaml — bump components to OBI's Collector release line:
  • Beta modules v0.145.0 → v0.151.0: debugexporter, otlpexporter, batchprocessor, otlpreceiver
  • Stable confmap providers v1.51.0 → v1.57.0: envprovider, fileprovider, httpprovider, httpsprovider, yamlprovider
• README.md — document the minimum compatible ocb version (v0.151.0+) and why it must track go.mod.
• CI — add .github/workflows/pull_request_otel_collector_example.yml that runs the ocb build on PRs/pushes touching examples/otel-collector/** or go.mod. It resolves the ocb version from go.mod so the example can't silently drift again.

Testing

Built locally with ocb/builder v0.151.0:

ocb --config ./builder-config.yaml
...
INFO  builder/main.go:150  Compiled  {"binary": "./otelcol-dev/otelcol-dev"}

Fixes #2264

🤖 Generated with Claude Code

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: hitkall / name: Hitesh Kalluru (d53ba92)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.23%. Comparing base (8a9be99) to head (a0e6efb).
⚠️ Report is 2 commits behind head on main.

❗ There is a different number of reports uploaded between BASE (8a9be99) and HEAD (a0e6efb). Click for more details.

HEAD has 44 uploads less than BASE

Flag	BASE (8a9be99)	HEAD (a0e6efb)
oats-test	9	0
k8s-integration-test	16	0
integration-test-arm	5	0
integration-test	10	0
integration-test-vm-6.18-lts	2	0
integration-test-vm-5.15-lts	2	0

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2420      +/-   ##
==========================================
- Coverage   69.10%   62.23%   -6.87%     
==========================================
  Files         325      324       -1     
  Lines       42650    35222    -7428     
==========================================
- Hits        29475    21922    -7553     
- Misses      11474    11859     +385     
+ Partials     1701     1441     -260     

Flag	Coverage Δ
integration-test	?
integration-test-arm	?
integration-test-vm-5.15-lts	?
integration-test-vm-6.18-lts	?
k8s-integration-test	?
oats-test	?
unittests	62.23% <ø> (-0.01%)	⬇️

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[MrAlias]

I'm hesitant to say "or later" here. There is no compatibility guarntee for that unstable package.

[hitkall]

Good point, agreed. I dropped the "or later" wording and pinned the doc to v0.151.0, with a note that ocb is an unstable v0.x package with no compatibility guarantee across versions, so the ocb version should match the component versions in builder-config.yaml. The CI job installs ocb at exactly the version resolved from go.mod, so it stays in lockstep too.

[MrAlias]

Awesome! Thanks for the fix