Switch to SWC Compiler

[Jakeii]

What does this change?

Migrate to use https://swc.rs for transpiling and minification instead of typescript and babel.

swc is widely used including by guardian/dotcom-rendering

Why?

SWC is much faster, and usually produces smaller bundle sizes, although in our case it's a very minor reduction in bundle size.

The numbers

Build times

Dev

# before
webpack 5.97.1 compiled successfully in 11699 ms
# after 
webpack 5.97.1 compiled successfully in 1270 ms

Prod

# before
webpack 5.97.1 compiled with 1 warning in 14376 ms
# after
webpack 5.97.1 compiled with 1 warning in 2038 ms

Bundle sizes

Including all prebid bundles

Before	After
2.07 MB (699.92 KB gzipped)	20.06 MB (698.48 KB gzipped)

Including just uk prebid bundle (More demonstrative as only one bundle is ever served to a user)

Before	After
612.76 KB (197.72 KB gzipped)	603.09 KB (196.91 KB gzipped)

[changeset-bot]

⚠️ No Changeset found

Latest commit: a52091f

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[github-actions]

Ad load time test results

For consented, top-above-nav took on average 4374ms to load.
For consentless, top-above-nav took on average 2774ms to load.

Test conditions:

• 5mbps download speed
• 1.5mbps upload speed
• 150ms latency

[github-actions]

Deploy build 2897 of dotcom::commercial-bundle to CODE

All deployment options

• Deploy build 2897 of dotcom::commercial-bundle to CODE
• Deploy parts of build 2897 to CODE by previewing it first
• What's on CODE right now?

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From guardian/actions-riff-raff.

[Jakeii]

this gives us nicer names for the localised prebid chunks