"Triple" should be renamed to "Tuple" to reflect the new terminology

[rami3l]

These are changes I expect would not break anything.

For context, main Rust repo has started moving to new terminology

originally by @tshepang in #4658 (comment)

Task List

• use "tuple" instead of "triple" for target names #4658
• use "tuple" instead of "triple" for target names (part 2) #4668
• use 'tuple' instead of 'triple' for env overrides #4743
• fix: rename partially "Triple" to "Tuple" to reflect the new terminology #4827
• fix: rename partially "Triple" to "Tuple" to reflect the new terminology (pt.2) #4834
• fix: rename partially "Triple" to "Tuple" to reflect the new terminology (pt.3) #4843
• chore: rename partially "Triple" to "Tuple" to reflect the new terminology #4849
• chore(settings): rename triple to tuple #4852

[rami3l]

My sincere appreciation to @tshepang for piloting the project and to @motorailgun @WaterWhisperer for all your efforts in reviving #4668 and pushing it towards the finish line :)