Add link in button for CPE firmware update

[epeach]

Previous implementation only had option to update firmware for CPC:

This PR adds a link to the Adafruit website which directs users how to flash the CPE firmware, since we are no longer pursuing flashing that automatically.

Both options are hidden behind 'flash-classic' experiment flag.
Next steps: implementing check for firmware implementation in CPFirmata.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (staging@2dd32ab). Click here to learn what that means.
The diff coverage is 0%.

@@            Coverage Diff             @@
##             staging   #30727   +/-   ##
==========================================
  Coverage           ?   71.96%           
==========================================
  Files              ?     1383           
  Lines              ?    85664           
  Branches           ?     3530           
==========================================
  Hits               ?    61652           
  Misses             ?    20706           
  Partials           ?     3306

Flag	Coverage Δ
#integration	55.75% <ø> (?)
#storybook	56.44% <ø> (?)
#unit	58.13% <0%> (?)

Impacted Files	Coverage Δ
apps/src/lib/kits/maker/ui/SetupChecklist.jsx	79.25% <0%> (ø)

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