[Docs] update outdated link to on-prem tutorial

[ALMerrill]

Tracking issue

https://github.com/flyteorg/flyte/issues/
Closes #4865

Why are the changes needed?

The link in the docs that points to the "hard way" tutorial for on-prem deployment is out of date

What changes were proposed in this pull request?

Updating the link. The link is found here, under this header: https://docs.flyte.org/en/latest/deployment/deployment/cloud_simple.html#flyte-in-on-premises-infrastructure

How was this patch tested?

The link that is being changed to is working, it just added the single-node folder

Screenshots

Old link

New link

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Docs link

https://docs.flyte.org/en/latest/deployment/deployment/cloud_simple.html#flyte-in-on-premises-infrastructure

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[neverett]

Thanks @ALMerrill! Looks like the DCO check is failing -- you should be able to sign off your commit and get the test to pass by following the steps in the "Rebase the branch" section here: https://github.com/flyteorg/flyte/pull/4868/checks?check_run_id=21381421828

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (104b95e) 59.56% compared to head (65c8133) 58.97%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4868      +/-   ##
==========================================
- Coverage   59.56%   58.97%   -0.59%     
==========================================
  Files         567      645      +78     
  Lines       41536    55162   +13626     
==========================================
+ Hits        24739    32533    +7794     
- Misses      14402    20054    +5652     
- Partials     2395     2575     +180     

Flag	Coverage Δ
unittests	58.97% <ø> (-3.47%)	⬇️

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