* feat: Helmfile V1 mode
We add a new "V1 mode" to Helmfile so that you can seemlessly upgrade Helmfile from the current v0.x to the upcoming v1.0.
The idea is that we build both v0 and v1 binaries from the same tagged commit within the main branch, with different defaults for the "V1 mode"- the V1 mode is disabled by default for v0.x binaries, while it is enabled by default for v1.x binaries.
The V1 mode can be overrode at runtime via envvar. That is, even after upgrading the binary to v1, you will not see any backward-incompatible changes while you explicitly set an envvar, `HELMFILE_V1MODE=true`, at runtime.
Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>
Signed-off-by: yxxhero <aiopsclub@163.com>
Yusuke Kuoka