[cmd/mdatagen] Enforce tab indentation in Go template files

[Goutham-Annem]

Description

Added a check-template-tabs Makefile target and a corresponding CI step in build-and-test.yml that fails if any .go.tmpl file under cmd/mdatagen or cmd/builder contains lines with leading spaces. Converted the two remaining offending templates (config_from_cfggen.go.tmpl and config_from_cfggen_test.go.tmpl) from space indentation to tab indentation to bring them in line with all other templates.

Link to tracking issue

Fixes #14698

Testing

Ran make check-template-tabs locally — passes with no output. All other .go.tmpl files were already tab-indented and continue to pass.

Documentation

No documentation changes needed. The check-template-tabs target is self-documenting via the Makefile.

Authorship

• I, a human, wrote this pull request description myself.

[codspeed-hq]

Merging this PR will create unknown performance changes

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⏩ 4 skipped benchmarks¹
🗄️ 2 archived benchmarks run²

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_{Comparing Goutham-Annem:fix/14698-check-template-tabs (a702d72) with main (fe96e04)}

Footnotes

1. 4 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. 2 benchmarks were run, but are now archived. If they were deleted in another branch, consider rebasing to remove them from the report. Instead if they were added back, click here to restore them. ↩

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.03%. Comparing base (52e6bf4) to head (bc52693).

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #15444   +/-   ##
=======================================
  Coverage   91.03%   91.03%           
=======================================
  Files         729      729           
  Lines       48491    48491           
=======================================
  Hits        44144    44144           
  Misses       3020     3020           
  Partials     1327     1327           

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