Update magic-string due to deprecated dependency

[jperelli]

npm i throws this warning

...
npm WARN deprecated sourcemap-codec@1.4.8: Please use @jridgewell/sourcemap-codec instead
...

npm ls sourcemap-codec says

└─┬ @sentry/esbuild-plugin@0.2.3
  └─┬ @sentry/bundler-plugin-core@0.2.3
    └─┬ magic-string@0.26.2
      └── sourcemap-codec@1.4.8

magic-string module CHANGELOG.md does not look like is making a breaking change from 0.26.2 to 0.27.0

[lforst]

Thanks for the PR! I am gonna do some manual tests here to verify this isn't actually breaking something. Just as a heads-up, minor version bumps on 0.x are actually considered breaking semver-spec wise.

[lforst]

Looks all good! Thank you for your contribution!