Fix Go test failure due to time zone changes (Closes: #1091811) and upload to unstable

Otto Kekäläinenrequested to merge
otto/golang-github-caarlos0-env:bugfix/1091811-go-test-timezone-failure into debian/latest

Fix Go test suite failures that caused FTBFS:

=== RUN   TestParsesEnv
  env_test.go:265: unexpected error: unknown time zone Europe/Berlin
--- FAIL: TestParsesEnv (0.00s)

Note that I wasn't able to reproduce the failure in https://salsa.debian.org/otto/golang-github-caarlos0-env/-/pipelines/806868 nor https://launchpadlibrarian.net/773490787/buildlog_ubuntu-plucky-amd64.golang-github-caarlos0-env_11.3.1-1~bpo25.04.1~1738188869.de7bd9d+debian.latest_BUILDING.txt.gz:

=== RUN   TestParsesEnv
--- PASS: TestParsesEnv (0.00s)

However, Santiago did provably see a failure as described in bug report https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1091811 and adding dependency on legacy tzdata is relatively safe to do for now.

Merge request reports