Upgrade gopkg.io/yaml from v2 to v3 in schema

[MrAlias]

Resolve #4533

Based on docs, internal code review, and testing, KnownFields is the equivalent of how we are currently using SetStrict.

[codecov]

Codecov Report

Merging #4535 (dc9375e) into main (bf54101) will decrease coverage by 0.1%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##            main   #4535     +/-   ##
=======================================
- Coverage   81.3%   81.3%   -0.1%     
=======================================
  Files        220     220             
  Lines      17678   17679      +1     
=======================================
- Hits       14386   14384      -2     
- Misses      2992    2994      +2     
- Partials     300     301      +1     

Files Changed	Coverage
schema/v1.0/parser.go	100.0%
schema/v1.1/parser.go	100.0%