fix: oidcHTTPClient now use proxy from environment

[sigurdvaa]

Description

Update transport setting for oidcHTTPClient so it can use proxy setting from the environment. This can be required for systems with limited firewall access, so that oidc issuer can be reached via a proxy.

Related Issue

• Fixes oidcHTTPClient doesn't use proxy settings from environment (http_proxy) causing authentication with external IdP to fail #3114

Motivation and Context

Makes it possible to authenticate using external IdP when OpenCloud system needs to use a http proxy for outoing http requests.

How Has This Been Tested?

• Needed firewall rule for authentication with external IdP even though OpenCloud system was configured to use http proxy. Verified Firewall rule was no longer needed after applying patch.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation added

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

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🟢 Metrics -17 duplication

Metric	Results
Duplication	-17

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