style: override linguist's default language detection

[mboersma]

Reason for Change:
Overrides the default language detection for github-linguist so Go template files aren't identified as Raku or Perl.

Before:

# github-linguist --breakdown
91.54%  Go
2.79%   Raku
2.61%   Shell
1.99%   PowerShell
0.90%   Perl
0.14%   Makefile
0.03%   Python
0.00%   Batchfile

After:

# github-linguist --breakdown
95.22%  Go
2.61%   Shell
1.99%   PowerShell
0.14%   Makefile
0.03%   Python
0.00%   Batchfile

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:
I realize this is entirely trivial, but it's the kind of thing that bothers me.

[codecov]

Codecov Report

Merging #3100 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3100   +/-   ##
=======================================
  Coverage   70.62%   70.62%           
=======================================
  Files         147      147           
  Lines       25407    25407           
=======================================
  Hits        17944    17944           
  Misses       6341     6341           
  Partials     1122     1122           

---

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[jackfrancis]

/lgtm