🌱 read in dockerfiles from stdin

[cahillsf]

What this PR does / why we need it:
this implements the workaround mentioned here: moby/buildkit#1368 (comment) for avoiding an incorrectly cached Dockerfile

All of the unmodified docker-build-* targets leverage the --build-arg package option and intentionally use the same Dockerfile located in the root dir change has been applied to each build target

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #9752

details of findings in this comment: #9752 (comment)

/area release

[k8s-ci-robot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[cahillsf]

waiting for this PR to be approved/merged then will take out of draft: https://github.com/kubernetes-sigs/cluster-api/pull/9932/files

[chrischdi]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: f21d817c9197cc9812ae07b252f92c48e5ef63d6

[chrischdi]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 03c7ee9fc6d8e506cb21a2a8449081a9e7a7e4d6

[sbueringer]

Thx!

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sbueringer

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[chrischdi]

/area ci

EDIT: wrong issue...

[chrischdi]

/remove-area ci

[cahillsf]

/cherry-pick release-1.6

[k8s-infra-cherrypick-robot]

@cahillsf: new pull request created: #10209

In response to this:

/cherry-pick release-1.6

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[cahillsf]

/cherry-pick release-1.5

[k8s-infra-cherrypick-robot]

@cahillsf: #9990 failed to apply on top of branch "release-1.5":

Applying: read in dockerfile from stdin
Using index info to reconstruct a base tree...
M	Makefile
Falling back to patching base and 3-way merge...
Auto-merging Makefile
CONFLICT (content): Merge conflict in Makefile
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 read in dockerfile from stdin
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherry-pick release-1.5

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.