ref(build): consolidate version Makefile variables

[nojnhuh]

Description:
This change combines the CLI_VERSION and CONTROLLER_VERSION Makefile variables into a single VERSION variable since they were being used for the same purpose.

Affected area:

• New Functionality [ ]
• Documentation [ ]
• Install [ ]
• Control Plane [ ]
• CLI Tool [ ]
• Certificate Management [ ]
• Networking [ ]
• Metrics [ ]
• SMI Policy [ ]
• Security [ ]
• Tests [ ]
• CI System [X]
• Performance [ ]
• Other [ ]

Please answer the following questions with yes/no.

• Does this change contain code from or inspired by another project? If so, did you notify the maintainers and provide attribution?
  No

[codecov-io]

Codecov Report

Merging #1936 into main will increase coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1936      +/-   ##
==========================================
+ Coverage   58.43%   58.50%   +0.06%     
==========================================
  Files         131      131              
  Lines        5266     5270       +4     
==========================================
+ Hits         3077     3083       +6     
+ Misses       2186     2184       -2     
  Partials        3        3              

Impacted Files	Coverage Δ
pkg/envoy/route/config.go	95.83% <0.00%> (+0.83%)	⬆️
pkg/injector/webhook.go	72.28% <0.00%> (+1.17%)	⬆️

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