cirrus: change alt arch task to only compile binaries

The current podman-release-%.tar.gz target does a lot more then just
checking if we can build for the given arch, in particular it first
builds a local podman-remote for the remote-docs.sh script. This makes
things slow as we compile several things and then builda and package the
docs. Given the docs are not arch specific there is realy no point in
doing all that work. All we care about is if the bianries can build on
other arches to catch compile issue for otherwise untested arches.

This should make the CI Alt Arch. tasks much faster.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Makefile

@@ -500,6 +500,14 @@ local-cross: $(CROSS_BUILD_TARGETS) ## Cross compile podman binary for multiple
 .PHONY: cross
 cross: local-cross
 
+# Simple target to check that we can build all binaries for another arch,
+# the resulting binaries are not meant to be useable this is just for
+# testing if it builds, it depends on the caller to set GOOS/GOARCH.
+.PHONY: cross-binaries
+cross-binaries:
+	$(MAKE) CGO_ENABLED=0 GOOS=$(GOOS) GOARCH=$(GOARCH) \
+		BUILDTAGS="$(BUILDTAGS_CROSS)" clean-binaries binaries; \
+
 .PHONY: completions
 completions: podman podman-remote
 	# key = shell, value = completion filename

contrib/cirrus/runner.sh

@@ -312,7 +312,7 @@ function _run_altbuild() {
 function _build_altbuild_archs() {
     for arch in "$@"; do
         msg "Building release archive for $arch"
-        showrun make podman-release-${arch}.tar.gz GOARCH=$arch
+        showrun make cross-binaries GOARCH=$arch
     done
 }