fix mdmproxy build by reverting back to previous but not filtering tags (#48264)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
remove if NA -->
**Related issue:** Resolves #

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

- [ ] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.

- [ ] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
- [ ] Timeouts are implemented and retries are limited to avoid infinite
loops
- [ ] If paths of existing endpoints are modified without backwards
compatibility, checked the frontend/CLI for any necessary changes

## Testing

- [ ] Added/updated automated tests
- [ ] Where appropriate, [automated tests simulate multiple hosts and
test for host
isolation](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/reference/patterns-backend.md#unit-testing)
(updates to one hosts's records do not affect another)

- [ ] QA'd all new/changed functionality manually

For unreleased bug fixes in a release candidate, one of:

- [ ] Confirmed that the fix is not expected to adversely impact load
test results
- [ ] Alerted the release DRI if additional load testing is needed

## Database migrations

- [ ] Checked schema for all modified table for columns that will
auto-update timestamps during migration.
- [ ] Confirmed that updating the timestamps is acceptable, and will not
cause unwanted side effects.
- [ ] Ensured the correct collation is explicitly set for character
columns (`COLLATE utf8mb4_unicode_ci`).

## New Fleet configuration settings

- [ ] Setting(s) is/are explicitly excluded from GitOps

If you didn't check the box above, follow this checklist for
GitOps-enabled settings:

- [ ] Verified that the setting is exported via `fleetctl
generate-gitops`
- [ ] Verified the setting is documented in a separate PR to [the GitOps
documentation](https://github.com/fleetdm/fleet/blob/main/docs/Configuration/yaml-files.md#L485)
- [ ] Verified that the setting is cleared on the server if it is not
supplied in a YAML file (or that it is documented as being optional)
- [ ] Verified that any relevant UI is disabled when GitOps mode is
enabled

## fleetd/orbit/Fleet Desktop

- [ ] Verified compatibility with the latest released version of Fleet
(see [Must
rule](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/workflows/fleetd-development-and-release-strategy.md))
- [ ] If the change applies to only one platform, confirmed that
`runtime.GOOS` is used as needed to isolate changes
- [ ] Verified that fleetd runs on macOS, Linux and Windows
- [ ] Verified auto-update works from the released version of component
to the new version (see [tools/tuf/test](../tools/tuf/test/README.md))


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Chores**
* Updated the container build process for the migration proxy so the
binary is built during image creation.
* Adjusted the runtime image packaging to copy the generated executable
from the build output location while keeping runtime behavior unchanged.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

tools/mdm/migration/mdmproxy/Dockerfile

@@ -1,13 +1,16 @@
 FROM golang:1.26.4-alpine3.23@sha256:f23e8b227fb4493eabe03bede4d5a32d04092da71962f1fb79b5f7d1e6c2a17f
 ARG TAG
-RUN go install github.com/fleetdm/fleet/v4/tools/mdm/migration/mdmproxy@${TAG}
+RUN apk update && apk add --no-cache git
+RUN git clone --branch "${TAG}" --depth=1 --progress --no-recurse-submodules https://github.com/fleetdm/fleet.git /go/fleet \
+    && cd /go/fleet/tools/mdm/migration/mdmproxy \
+    && go build -o /go/fleet/tools/mdm/migration/mdmproxy/mdmproxy .
 
 FROM alpine:3.23.4@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 LABEL maintainer="Fleet Developers"
 
 RUN apk --no-cache upgrade openssl libcrypto3 libssl3 \
     && apk add --no-cache tini
-COPY --from=0 /go/bin/mdmproxy /usr/bin/mdmproxy
+COPY --from=0 /go/fleet/tools/mdm/migration/mdmproxy/mdmproxy /usr/bin/mdmproxy
 ADD --chmod=0755 ./entrypoint.sh /usr/bin/entrypoint.sh
 
 # Create mdmproxy group and user