.github/workflows/mpremote.yml: Fetch full history.

[jimmo]

Instead of doing the shallow checkout followed by an unshallow-with-tags, just set fetch-depth=0 to get the full history to start with.

This prevents the issue we saw with the v1.20.0 release where the github checkout action does

git fetch --no-tags --prune --progress --no-recurse-submodules --depth=1000 origin +294baf52b346e400e2255c6c1e82af5b978b18f7:refs/tags/v1.20.0

(in effect creating a "fake" v1.20.0 tag in the local repo)

and then our workflow gets the tags and history by doing

git fetch --prune --tags --unshallow

which then attempts to clobber the v1.20.0 tag with the real one.

[dhalbert]

For CircuitPython, we looked into partial clones (--filter=blob:none and --filter=tree:0), which look like a full fetch but are actualy lazy, and fetch missing things on demand. These have been around for a while, though for submodules --filter has been added to git only more recently:
adafruit#7225
adafruit#7763
adafruit#7788

[github-actions]

Code size report:

   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
        rp2:    +0 +0.000% PICO

[jimmo]

See also discussion and linked PRs at actions/checkout#701

[dpgeorge]

Thanks!