Update dependencies in go.mod and go.sum (#236)

Upgraded `github.com/nats-io/nkeys` to v0.4.9, `golang.org/x/crypto` to v0.31.0, and `golang.org/x/sys` to v0.28.0. These updates ensure compatibility with the latest changes and include potential bug fixes and improvements. No functional changes were introduced in the codebase.

Signed-off-by: Alberto Ricart <[email protected]>

v2/go.mod

@@ -2,14 +2,14 @@ module github.com/nats-io/jwt/v2
 
 go 1.22
 
-require github.com/nats-io/nkeys v0.4.8
+require github.com/nats-io/nkeys v0.4.9
 
 retract (
 	v2.7.1 // contains retractions only
 	v2.7.0 // includes case insensitive changes to tags that break jetstream placement
 )
 
 require (
-	golang.org/x/crypto v0.29.0 // indirect
-	golang.org/x/sys v0.27.0 // indirect
+	golang.org/x/crypto v0.31.0 // indirect
+	golang.org/x/sys v0.28.0 // indirect
 )

v2/go.sum

@@ -1,6 +1,6 @@
-github.com/nats-io/nkeys v0.4.8 h1:+wee30071y3vCZAYRsnrmIPaOe47A/SkK/UBDPdIV70=
-github.com/nats-io/nkeys v0.4.8/go.mod h1:kqXRgRDPlGy7nGaEDMuYzmiJCIAAWDK0IMBtDmGD0nc=
-golang.org/x/crypto v0.29.0 h1:L5SG1JTTXupVV3n6sUqMTeWbjAyfPwoda2DLX8J8FrQ=
-golang.org/x/crypto v0.29.0/go.mod h1:+F4F4N5hv6v38hfeYwTdx20oUvLLc+QfrE9Ax9HtgRg=
-golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
-golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+github.com/nats-io/nkeys v0.4.9 h1:qe9Faq2Gxwi6RZnZMXfmGMZkg3afLLOtrU+gDZJ35b0=
+github.com/nats-io/nkeys v0.4.9/go.mod h1:jcMqs+FLG+W5YO36OX6wFIFcmpdAns+w1Wm6D3I/evE=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=