Ensure that file modified time is set correctly

Commit e435bc6 introduced behavior in
creating the source-dist archive that sets the file modification time to
the same time as the most recent `git` commit. This facilitates
reproducible builds, but it also has an issue. The code sets `TZ=`,
which means that on systems running in time zones which aren't UTC, the
modification time will be in the future (or past).

Up until recently, this only resulted in GNU make printing warnings
about modification times being in the future. However, with recent
changes in how escripts are built, this results in an "infinite make
loop" that is described in #14440
and #14443

The solution is to _not_ hard-code the `TZ` value when calculating the
time of the most recent `git` commit.

Remove `TZ=` as it is the root cause of #14440

Author: lukebakken

Makefile

@@ -189,7 +189,7 @@ $(1): $(ERLANG_MK_RECURSIVE_DEPS_LIST)
 	$${gen_verbose} $${RSYNC} $(2) ./ $$@/
 	$${verbose} echo "$(PROJECT_DESCRIPTION) $(PROJECT_VERSION)" > $$@/git-revisions.txt
 	$${verbose} echo "$(PROJECT) $$$$(git rev-parse HEAD) $$$$(git describe --tags --exact-match 2>/dev/null || git symbolic-ref -q --short HEAD)" >> $$@/git-revisions.txt
-	$${verbose} echo "$$$$(TZ= git --no-pager log -n 1 --format='%cd' --date='format-local:%Y%m%d%H%M.%S')" > $$@.git-times.txt
+	$${verbose} echo "$$$$(git --no-pager log -n 1 --format='%cd' --date='format-local:%Y%m%d%H%M.%S')" > $$@.git-times.txt
 	$${verbose} cat packaging/common/LICENSE.head > $$@/LICENSE
 	$${verbose} mkdir -p $$@/deps/licensing
 	$${verbose} set -e; for dep in $$$$(cat $(ERLANG_MK_RECURSIVE_DEPS_LIST) | LC_COLLATE=C sort); do \
@@ -216,7 +216,7 @@ $(1): $(ERLANG_MK_RECURSIVE_DEPS_LIST)
 		 echo "$$$$(basename "$$$$dep") $$$$(git rev-parse HEAD) $$$$(git describe --tags --exact-match 2>/dev/null || git symbolic-ref -q --short HEAD)") \
 		 >> "$$@/git-revisions.txt"; \
 		! test -d $$$$dep/.git || (cd $$$$dep; \
-		 echo "$$$$(env TZ= git --no-pager log -n 1 --format='%cd' --date='format-local:%Y%m%d%H%M.%S')") \
+		 echo "$$$$(git --no-pager log -n 1 --format='%cd' --date='format-local:%Y%m%d%H%M.%S')") \
 		 >> "$$@.git-times.txt"; \
 	done
 	$${verbose} cat packaging/common/LICENSE.tail >> $$@/LICENSE