fix(longevity): restore contents of "longevity-mv-si-4days.jenkinsfile"

[lersek]

Commit d722f0d38a6d ("test(tier1): Use streaming for
longevity-mv-si-4days.jenkinsfile test", 2024-09-11) intended to do four
things:

(1) create an *unmodified* copy of
    "tier1/longevity-mv-si-4days.jenkinsfile" as
    "longevity/longevity-mv-si-4days.jenkinsfile";

(2) create a *modified* copy of the same
    "tier1/longevity-mv-si-4days.jenkinsfile" as
    "tier1/longevity-mv-si-4days-streaming.jenkinsfile", with the
    modification being the addition of "configurations/disable_rbno.yaml"
    to the test config;

(3) redirect triggers from the original
    "tier1/longevity-mv-si-4days.jenkinsfile" to the modified copy created
    in (2);

(4) remove the original "tier1/longevity-mv-si-4days.jenkinsfile".

Step (1) was implemented incorrectly. The file created in step (1) is not
an *unmodified* copy; today it is identical to the *modified* copy from
step (2).

Restore the actual original contents in
"longevity/longevity-mv-si-4days.jenkinsfile".

Testing

• https://jenkins.scylladb.com/view/staging/job/scylla-staging/job/laszlo.ersek/job/longevity-mv-si-4days/2/

PR pre-checks (self review)

• I added the relevant backport labels (commit d722f0d is contained by branch-6.2 and branch-perf-v16, and it had been cherry-picked to branch-2024.2 as commit 46b2a15)
• I didn't leave commented-out/debugging code

Reminders

• Add New configuration option and document them (in sdcm/sct_config.py)
• Add unit tests to cover my changes (under unit-test/ folder)
• Update the Readme/doc folder relevant to this change (if needed)

[fruch]

LGTM

[pehala]

LGTM, sorry for the mistake

[lersek]

Thanks.