[receiver/lightprometheus] Deprecate receiver

[crobert-1]

Testing:

$ ./bin/otelcol_darwin_arm64 --config config.yaml 
2025/11/18 10:19:24 settings.go:708: Set config to [config.yaml]
2025/11/18 10:19:24 settings.go:708: Set memory limit to 460 MiB
2025/11/18 10:19:24 settings.go:708: Set soft memory limit set to 460 MiB
2025/11/18 10:19:24 settings.go:708: Set garbage collection target percentage (GOGC) to 400
2025/11/18 10:19:24 settings.go:708: set "SPLUNK_LISTEN_INTERFACE" to "0.0.0.0"
2025-11-18T10:19:24.217-0800	info	builders/builders.go:26	Deprecated component. Will be removed in future releases.	{"resource": {"service.instance.id": "fa902735-31b5-4476-8cb2-4d946c42c9a2", "service.name": "otelcol", "service.version": "v0.138.0-46-gbfc361dd"}, "otelcol.component.id": "lightprometheus", "otelcol.component.kind": "receiver", "otelcol.signal": "metrics"}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 37.95%. Comparing base (d0dfb3d) to head (845abcb).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6949      +/-   ##
==========================================
+ Coverage   37.92%   37.95%   +0.03%     
==========================================
  Files         367      367              
  Lines       25751    25751              
==========================================
+ Hits         9765     9774       +9     
+ Misses      15171    15165       -6     
+ Partials      815      812       -3     

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[Copilot]

Pull Request Overview

This PR deprecates the lightprometheus receiver by changing its stability level from development to deprecated. Users are directed to use the standard Prometheus or Simple Prometheus receivers instead.

• Changed stability level from StabilityLevelDevelopment to StabilityLevelDeprecated in the receiver factory
• Updated README.md documentation to reflect deprecated status with warning message
• Added changelog entry documenting the deprecation

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
internal/receiver/lightprometheusreceiver/factory.go	Updated stability level to StabilityLevelDeprecated
internal/receiver/lightprometheusreceiver/README.md	Updated status table and added deprecation warning with alternative receivers
.chloggen/deprecate_light_prom.yaml	Added changelog entry documenting the deprecation

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