Core: Remove `handlebars` usage

Closes #29167

What I did

I removed the need for / use of handlebars

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

[ ] stories
[ ] unit tests
[ ] integration tests
[ ] end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

[ ] Add or update documentation reflecting your changes
[ ] If you are deprecating/removing a feature, make sure to update MIGRATION.MD

Checklist for Maintainers

[ ] When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts
[ ] Make sure this PR contains one of the labels below:

Available labels
- `bug`: Internal changes that fixes incorrect behavior. - `maintenance`: User-facing maintenance tasks. - `dependencies`: Upgrading (sometimes downgrading) dependencies. - `build`: Internal-facing build tooling & test updates. Will not show up in release changelog. - `cleanup`: Minor cleanup style change. Will not show up in release changelog. - `documentation`: Documentation **only** changes. Will not show up in release changelog. - `feature request`: Introducing a new feature. - `BREAKING CHANGE`: Changes that break compatibility in some way with current major version. - `other`: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

_core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>_

name	before	after	diff	z	%
createSize	0 B	0 B	0 B	-	-
generateSize	77.5 MB	77.7 MB	202 kB	4.29	0.3%
initSize	162 MB	162 MB	-139 kB	-1.52	-0.1%
diffSize	84.8 MB	84.5 MB	-340 kB	-3.44	-0.4%
buildSize	6.96 MB	6.96 MB	0 B	-2.08	0%
buildSbAddonsSize	1.57 MB	1.57 MB	0 B	-2.38	0%
buildSbCommonSize	195 kB	195 kB	0 B	-	0%
buildSbManagerSize	1.91 MB	1.91 MB	0 B	-1.83	0%
buildSbPreviewSize	311 kB	311 kB	0 B	-2.38	0%
buildStaticSize	0 B	0 B	0 B	-	-
buildPrebuildSize	3.98 MB	3.98 MB	0 B	-2.03	0%
buildPreviewSize	2.97 MB	2.97 MB	0 B	-2.38	0%
testBuildSize	0 B	0 B	0 B	-	-
testBuildSbAddonsSize	0 B	0 B	0 B	-	-
testBuildSbCommonSize	0 B	0 B	0 B	-	-
testBuildSbManagerSize	0 B	0 B	0 B	-	-
testBuildSbPreviewSize	0 B	0 B	0 B	-	-
testBuildStaticSize	0 B	0 B	0 B	-	-
testBuildPrebuildSize	0 B	0 B	0 B	-	-
testBuildPreviewSize	0 B	0 B	0 B	-	-

name	before	after	diff	z	%
createTime	15.6s	14.5s	-1s -61ms	0.79	-7.3%
generateTime	20.8s	21.1s	226ms	-0.25	1.1%
initTime	16.3s	14.6s	-1s -644ms	-0.65	-11.2%
buildTime	8.6s	8.3s	-314ms	-1.95	-3.8%
testBuildTime	0ms	0ms	0ms	-	-
devPreviewResponsive	6.3s	6.5s	112ms	-0.71	1.7%
devManagerResponsive	4.2s	4.2s	75ms	-0.81	1.7%
devManagerHeaderVisible	521ms	518ms	-3ms	-1.92	-0.6%
devManagerIndexVisible	548ms	556ms	8ms	-1.79	1.4%
devStoryVisibleUncached	970ms	995ms	25ms	-0.87	2.5%
devStoryVisible	549ms	556ms	7ms	-1.85	1.3%
devAutodocsVisible	493ms	494ms	1ms	-1.23	0.2%
devMDXVisible	478ms	481ms	3ms	-1.36	0.6%
buildManagerHeaderVisible	520ms	470ms	-50ms	-1.81	🔰-10.6%
buildManagerIndexVisible	558ms	471ms	-87ms	-1.9	🔰-18.5%
buildStoryVisible	594ms	547ms	-47ms	-1.94	🔰-8.6%
buildAutodocsVisible	442ms	454ms	12ms	-1.76	2.6%
buildMDXVisible	438ms	417ms	-21ms	-1.74	🔰-5%

Greptile Summary

This PR removes the Handlebars dependency from Storybook, simplifying string manipulation in the codebase.

Replaced Handlebars template with JavaScript file in code/builders/builder-webpack5/templates/virtualModuleModernEntry.js
Updated code/builders/builder-webpack5/src/preview/virtual-module-mapping.ts to use string replacement instead of Handlebars
Removed handlebars dependency from code/core/package.json and related utility in code/core/src/common/utils/handlebars.ts
Eliminated code/builders/builder-webpack5/templates/virtualModuleModernEntry.js.handlebars

storybookjs / storybook