Information from Daniel Micay <danielmicay@gmail.com>:

SoC firmware anti-rollback protection is being actively used for 6th and
7th generation Pixels. The code implementing this was deployed as part
of Android 13 resulting in an initial rollback version increase.

Consider the situation where a device shipped with v5 firmware and was
upgraded to v7 by the user. It has v7 on the current slot and v5 on the
alternate slot. It has been successfully booted with v7 firmware so the
OS has incremented the rollback version to v7. If the user unlocks and
unsuccessfully flashes new firmware or a new OS, the device rolls back
to the other slot, bricking itself.

The safest solution to this problem is flashing the unused slot with the
new firmware, making it active, booting it and then repeating it. This
makes sure that the new firmware is flashed to both slots and verifies
that it boots up successfully before proceeding with flashing the OS.

It makes sense to do this for ALL devices because all devices can deploy
similar anti-rollback protection and this also improves overall safety
of installation. Anti-rollback protection isn't the only reason that the
inactive slot could have non-booting firmware. Something could have gone
wrong previously so the user only has 1 booting firmware slot remaining.
This new approach makes fastboot.js much safer than Google's approach to
flashing.

GrapheneOS has adopted this for both fastboot.js and also the CLI
flashing script in the factory images zip since shortly after the
release of Android 13. It's very well tested now and we've avoided the
issues with bricked devices people are experiencing with flashing the
stock OS.

Raw images can be quite large, and it might not be possible to convert
the images in RAM, on low memory devices, as raw to sparse conversion
can consume memory more than twice the size of the image being
converted. This commit also reduces fastboot.js peak memory usage
during flashing.

Remove better-docs and jsdoc dependencies, which are used for building
documentation. The documentation hasn't been updated by upstream and
script to build it is broken anyway. I think it is better to just drop
support for building documentation than maintain it downstream. This
commit also fixes warnings shown by package manager when installing
dependencies.

Explicitly add dependencies required by @rollup/plugin-typescript, which
were previously installed implicitly:
- tslib 2.5.0
- typescript 5.0.4

update rollup to 3.20.5 and its plugins:
- update @rollup/plugin-node-resolve to 15.0.2
- update @rollup/plugin-typescript to 11.1.0
- replace deprecated rollup-plugin-terser with @rollup/plugin-terser 0.4.1

update other dependencies:
- @types/w3c-web-usb to 1.0.6
- eslint to 8.38.0
- eslint-config-prettier to 8.8.0
- prettier to 2.8.7

Also, run 'yarn upgrade` to upgrade dependencies in yarn.lock to their
latest versions, as per ranges specified in package.json.

Also add support for updating files in dist/vendor during build step.

Also add support for updating Pako files in dist/vendor during build step.

This fixes "Argument of type 'unknown' is not assignable to parameter of
type 'Error'" warning shown during compilation. The error type may not
necessarily be of type Error, the caller should narrow the error down to
specific types.

The nested images zip is uncompressed and can be read from directly.
This results in reduced storage usage (as the nested images zip doesn't
need to extracted into a blob first) and slightly faster flashing times
on low end and mobile devices (as there is no "unpack images" step).

See the corresponding fastboot commit for more info.

Zip entries are now contained in an outer directory.