fix(config): avoid recursion when interpolating env

[pi0]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

originally reported by @hartmut-co-uk in discord following config makes maximum call stack error:

  privateRuntimeConfig: {
    API_SECRET: '${API_SECRET}'
  },

It is also reproducible with dotenv-expand itself when using variable as value. Since we are using forked version there is this PR but have to also fix for upstream.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly. (PR: #)
• I have added tests to cover my changes (if not applicable, please state why)
• All new and existing tests are passing.

[codecov-commenter]

Codecov Report

Merging #8014 into dev will decrease coverage by 0.05%.
The diff coverage is 20.00%.

@@            Coverage Diff             @@
##              dev    #8014      +/-   ##
==========================================
- Coverage   68.87%   68.82%   -0.06%     
==========================================
  Files          91       91              
  Lines        3849     3852       +3     
  Branches     1044     1046       +2     
==========================================
  Hits         2651     2651              
- Misses        971      973       +2     
- Partials      227      228       +1     

Flag	Coverage Δ
#unittests	68.82% <20.00%> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
packages/config/src/load.js	75.28% <20.00%> (-2.63%)	⬇️

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[clarkdo]

What about giving a warning message here?

[pi0]

@clarkdo Making sense. I also improved logic to early stop to avoid duplicate values: