build-sys: Drop some dead code

- The ci/Dockerfile.fcos has been unused for some time and
  testing with FCOS derivatives is already done outside of CI
  here
- Drop the bits which reference git in the Makefile, a new rule
  I'm trying to impose here is that nothing in the build system
  should rely on git (or at least not rely on being built
  from a git repository)

Signed-off-by: Colin Walters <walters@verbum.org>

Author: cgwalters

Makefile

@@ -25,10 +25,6 @@
 
 prefix ?= /usr
 
-SOURCE_DATE_EPOCH ?= $(shell git log -1 --pretty=%ct)
-# https://reproducible-builds.org/docs/archives/
-TAR_REPRODUCIBLE = tar --mtime="@${SOURCE_DATE_EPOCH}" --sort=name --owner=0 --group=0 --numeric-owner --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime
-
 # Enable rhsm if we detect the build environment is RHEL-like.
 # We may in the future also want to include Fedora+derivatives as
 # the code is really tiny.
@@ -94,9 +90,6 @@ install-initramfs-dracut: install-initramfs
 install-all: install install-ostree-hooks
 	install -D -m 0755 target/release/tests-integration $(DESTDIR)$(prefix)/bin/bootc-integration-tests
 
-bin-archive: all
-	$(MAKE) install DESTDIR=tmp-install && $(TAR_REPRODUCIBLE) --zstd -C tmp-install -cf target/bootc.tar.zst . && rm tmp-install -rf
-
 build-unit-tests:
 	cargo t --no-run