[Universal profiling symbolizer] revert use of secrets variables

[endorama]

Proposed commit message

Revert "[Universal profiling symbolizer] use secrets variables (#9807)"

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Author's Checklist

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How to test this PR locally

Related issues

• [profiling] unable to load page error when onboarding using version 8.14.0  #9845

Screenshots

[inge4pres]

Question for the Fleet team (@kpollich ?): what happens if we don't upgrade the version, but still perform a rollback to the previous format?
Is the 8.14.0 version going to be overridden in EPR after merge?

That would solve our problem immediately.

[endorama]

@inge4pres I remember versions are immutable once released, so we would end up with 8.14.0 remaining the same.

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

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[elasticmachine]

💚 Build Succeeded

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[elasticmachine]

Package profiler_symbolizer - 8.14.1 containing this change is available at https://epr.elastic.co/search?package=profiler_symbolizer