Update munit diff in native branch

[majk-p]

Current combination of weaver and munit diff fails to link in fs2-data with an error:

[error] Unknown type munit.diff.Diff, referenced from:                                                                                                    
[error]          method weaver.Comparison$$anon$1.diff(java.lang.Object, java.lang.Object): weaver.Comparison$Result at Comparison.scala:48               
[error]          method weaver.internals.ExpectSame.eql(java.lang.Object, java.lang.Object, weaver.Comparison, weaver.SourceLocation): weaver.Expectations
 at ExpectSame.scala:15                                                                                                                                   
[error]          method weaver.Expect.eql(java.lang.Object, java.lang.Object, weaver.Comparison, weaver.SourceLocation): weaver.Expectations at Expect.sca
la:5                                                                                                                                                      
[error]  private method fs2.data.mft.ESPSpec$.$anonfun$new$2(scala.collection.immutable.List): weaver.Expectations at ESPSpec.scala:103                   
[error]          method fs2.data.mft.ESPSpec$$$Lambda$1.apply(java.lang.Object): java.lang.Object at ESPSpec.scala:102                                    
[error]  private method fs2.data.mft.ESPSpec$.$anonfun$new$1(fs2.data.esp.ESP): cats.effect.IO at ESPSpec.scala:102                                       
[error]          method fs2.data.mft.ESPSpec$$$Lambda$3.apply(java.lang.Object): java.lang.Object at ESPSpec.scala:74                                     
[error]     constructor fs2.data.mft.ESPSpec$() at ESPSpec.scala:74                                                                                       
[error]          method fs2.data.mft.ESPSpec$$SN$ReflectivelyInstantiate$.apply(): java.lang.Object at ESPSpec.scala:44                                   
[error] static constructor fs2.data.mft.ESPSpec$ at ESPSpec.scala:44                                                                                      
[error]    

Updating munit diff to 1.2.0 solves the linking issue

[zainab-ali]

I think there's a bug in the shading logic.

When including munit diff, we expected it to be shaded and so exempt from these issues. I think we need to look into how shading works with Scala.js.