go/runtime: Support bundle components without ELF binary

[kostko]

Fixes #5780

[netlify]

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Name	Link
🔨 Latest commit	7048cbb
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[codecov]

Codecov Report

Attention: Patch coverage is 53.84615% with 18 lines in your changes missing coverage. Please review.

Project coverage is 65.01%. Comparing base (5d54347) to head (af9deb9).
Report is 1 commits behind head on master.

Files	Patch %	Lines
go/runtime/registry/config.go	54.83%	11 Missing and 3 partials ⚠️
go/runtime/bundle/manifest.go	50.00%	1 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5838      +/-   ##
==========================================
- Coverage   65.49%   65.01%   -0.48%     
==========================================
  Files         621      621              
  Lines       63439    63451      +12     
==========================================
- Hits        41548    41255     -293     
- Misses      17041    17346     +305     
  Partials     4850     4850              

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