Use erlang < 25 on EL8

[amanda11]

Update Bash installer for 3.7 to use erlang24*

RabbitMQ have released a newer version 3.10.2 which now manages to start with erlang 25. But they still report on https://www.rabbitmq.com/which-erlang.html that the erlang 25 support is preview.
Therefore probably safer to stick with using 24*

[amanda11]

@armab I've cherrypicked the st2-packages for the 3.7 branch in this PR, but I'd appreciate your check as to process to what we need to do to cherry pick for 3.7. We shouldn't need new packages built as its just the bash installer we're updateing.

As per @bishopbm1 comment in slack, the new RabbitMQ 3.10.2 will now start with erlang 25 so even without this change we should be able to install ok now on EL8. But given that erlang 25 is "preview" support, would it still be better to use 24.* on erlang anyway.

[arm4b]

Thanks!

[arm4b]

The latest stable branch is referenced in the st2_bootstrap.sh script which is an entry point for the curl|bash installer.

st2-packages/scripts/st2_bootstrap.sh

Lines 18 to 19 in ed1cfe2

	# Note: This variable needs to default to a branch of the latest stable release
	BRANCH='v3.7'

From that, the installer will poin to the v3.7 branch scripts here:

st2-packages/scripts/st2_bootstrap.sh

Line 166 in ed1cfe2

ST2BOOTSTRAP="${BASE_PATH}/${BRANCH}/scripts/st2bootstrap-el${RHMAJVER}.sh"

[cognifloyd]

Yeah, let's stick with erlang 24 for now.