chore: remove failing request units test

[jstarry]

Problem

Now that the request units instruction is deprecated by the runtime, the test validator fails any transactions which use it.

Summary of Changes

• Remove failing test
• Mark ComputeBudget.requestUnits function as deprecated

Fixes #

[codecov]

Codecov Report

Merging #27735 (b78b97d) into master (e779032) will increase coverage by 0.4%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #27735     +/-   ##
=========================================
+ Coverage    76.9%    77.3%   +0.4%     
=========================================
  Files          48       55      +7     
  Lines        2505     2888    +383     
  Branches      355      402     +47     
=========================================
+ Hits         1927     2234    +307     
- Misses        448      513     +65     
- Partials      130      141     +11