Update es-module-shims to 1.5.5

[denschub]

es-module-shims version 1.5.5 fixes a timing issue affecting Firefox and Safari, resulting in the turbo:load event sometimes never firing. This would also fix hotwired/turbo-rails#286

I would submit a PR, but unfortunately I could not find any documentation on how the minified version was built.

[denschub]

Someone submitted #128, which would fix this.