feat: remove sourcemaps

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🚀 Feature: Remove sourcemap: true from tsup.config.ts #1909
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Per discussions linked in the issue, removes sourcemaps to significantly reduce the size of output files.

Target	Package Size	Unpacked Size	Total Files
main	106.7 kB	609.9 kB	277
remove-sourcemaps	54.1 kB	369.9 kB	186
Comparison	49% smaller	39% smaller	32% smaller

Raw npm pack output on main:

npm notice Tarball Details
npm notice name: create-typescript-app
npm notice version: 2.2.0
npm notice filename: create-typescript-app-2.2.0.tgz
npm notice package size: 106.7 kB
npm notice unpacked size: 609.9 kB
npm notice shasum: dd0439e3a977c55bbfaa8449f73799314b925368
npm notice integrity: sha512-Z0nBEgLroJY5p[...]yi9LJdG28f9DA==
npm notice total files: 277

Raw npm pack output with this change:

npm notice Tarball Details
npm notice name: create-typescript-app
npm notice version: 2.2.0
npm notice filename: create-typescript-app-2.2.0.tgz
npm notice package size: 54.1 kB
npm notice unpacked size: 369.9 kB
npm notice shasum: 8f92517ecbd9dbffdba72b5dd11aeceaf7d61b9b
npm notice integrity: sha512-OaNzBaDi41IH5[...]HospZHaW1trEQ==
npm notice total files: 186

[github-actions]

PR Compliance Checks Passed!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.48%. Comparing base (5e594f1) to head (3b90a60).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1963      +/-   ##
==========================================
- Coverage   95.48%   95.48%   -0.01%     
==========================================
  Files          90       90              
  Lines        3636     3635       -1     
  Branches      214      214              
==========================================
- Hits         3472     3471       -1     
  Misses        164      164              

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[github-actions]

🎉 This is included in version v2.3.0 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀