unrelated files are being sent to buildkit on COPYs

[alexcb]

consider build our deps from within a local context:

$ cd ~/gh/earthly/earthly # where I keep it locally
$ ./earthly -V +deps

deps only has a single COPY:

COPY go.mod go.sum ./

unrelated files are being sent:

             context | sent data for release/yum-repo/output/repo/packages/earthly-0.5.10-1.armv7l.rpm (11 MB)
             context | sent data for release/yum-repo/output/repo/packages/earthly-0.5.12-1.x86_64.rpm (6.5 MB)
             context | sent data for release/yum-repo/output/repo/packages/earthly-0.5.12-1.aarch64.rpm (11 MB)
             context | sent data for main (31 MB)
             context | sent data for release/yum-repo/output/repo/packages/earthly-0.5.12-1.armv7l.rpm (11 MB)
             context | sent data for release/yum-repo/output/repo/repodata/1f1b06d392f52ca0d1a6e12235b527de89007639c5276e93af2c224892c78bc8-other.xml.gz (397 B)
             context | sent data for release/yum-repo/output/repo/repodata/2bd8f905bb02d36c72774478b199d8e6e92727afef21aee245b9bd4a03ffa884-primary.xml.gz (871 B)
             context | sent data for release/yum-repo/output/repo/repodata/2d414c1fde7cdbe66623f8c6126fa11af7986a4a1a23d12c816f420e8b21f0d8-primary.sqlite.bz2 (3.4 kB)

This resulted in way too much data being sent:

transferred 801 file(s) for context . (258 MB, 1118 file/dir stats)

if I rerun earthly -V +deps, these files are cached; however earthly will still walk the dir sendinf file stats:

context | transferred 0 file(s) for context . (60 kB, 1118 file/dir stats)

When I would expect to only send file stats for go.mod and go.sum.

[alexcb]

#1085 introduced a new feature which can be enabled via:

VERSION --use-copy-include-patterns 0.5 

which will set the underlying include pattern option in buildkit, which limit which files are sent for each build context.