Fix waves 'double' to 'float' truncation warning

[Crola1702]

🦟 Bug fix

Fixes #osrf/buildfarm-tools#92 (comment)

Summary

Reference builds:

• https://build.osrfoundation.org/job/gz_rendering-8-win/85/
• https://build.osrfoundation.org/job/gz_rendering-7-win/77/

Warning:

• Present in waves.cc:171

Log output:

  waves.cc

C:\J\workspace\gz_rendering-7-win\ws\gz-rendering\test\integration\waves.cc(170,29): warning C4305: 'initializing': truncation from 'double' to 'float' [C:\J\workspace\gz_rendering-7-win\ws\build\gz-rendering7\test\integration\INTEGRATION_waves.vcxproj]

C:\J\workspace\gz_rendering-7-win\ws\gz-rendering\test\integration\waves.cc(174,28): warning C4305: 'initializing': truncation from 'double' to 'float' [C:\J\workspace\gz_rendering-7-win\ws\build\gz-rendering7\test\integration\INTEGRATION_waves.vcxproj]

  waves.obj : MSIL .netmodule or module compiled with /GL found; restarting link with /LTCG; add /LTCG to the link command line to improve linker performance

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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