rebase: bump golang.org/x/crypto from 0.5.0 to 0.6.0

Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.5.0 to 0.6.0.
- [Release notes](https://github.com/golang/crypto/releases)
- [Commits](https://github.com/golang/crypto/compare/v0.5.0...v0.6.0)

---
updated-dependencies:
- dependency-name: golang.org/x/crypto
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/golang.org/x/crypto/curve25519/internal/field/fe_generic.go

@@ -245,7 +245,7 @@ func feSquareGeneric(v, a *Element) {
 	v.carryPropagate()
 }
 
-// carryPropagate brings the limbs below 52 bits by applying the reduction
+// carryPropagateGeneric brings the limbs below 52 bits by applying the reduction
 // identity (a * 2²⁵⁵ + b = a * 19 + b) to the l4 carry. TODO inline
 func (v *Element) carryPropagateGeneric() *Element {
 	c0 := v.l0 >> 51