fix: govulncheck-finding-x-crypto (#4245)

```
Vulnerability #1: GO-2026-6355
    Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh
  More info: https://pkg.go.dev/vuln/GO-2026-6355
  Module: golang.org/x/crypto
    Found in: golang.org/x/crypto@v0.55.0
    Fixed in: golang.org/x/crypto@v0.56.0
    Example traces found:
      #1: net/redistest/redistest.go:60:51: redistest.newTestRedisWithOptions calls testcontainers.GenericContainer, which eventually calls ssh.NewClientConn

Vulnerability #2: GO-2026-6354
    Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh
  More info: https://pkg.go.dev/vuln/GO-2026-6354
  Module: golang.org/x/crypto
    Found in: golang.org/x/crypto@v0.55.0
    Fixed in: golang.org/x/crypto@v0.56.0
    Example traces found:
      #1: net/redistest/redistest.go:60:51: redistest.newTestRedisWithOptions calls testcontainers.GenericContainer, which eventually calls ssh.NewClientConn
```

So only in test supporting packages

Signed-off-by: Sandor Szücs <sandor.szuecs@zalando.de>

Author: szuecs

go.mod

@@ -67,7 +67,7 @@ require (
 	go.opentelemetry.io/otel/sdk/metric v1.46.0
 	go.opentelemetry.io/otel/trace v1.46.0
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba
-	golang.org/x/crypto v0.55.0
+	golang.org/x/crypto v0.56.0
 	golang.org/x/exp v0.0.0-20251209150349-8475f28825e9
 	golang.org/x/net v0.58.0
 	golang.org/x/oauth2 v0.36.0

go.sum

@@ -823,8 +823,8 @@ golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
-golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
+golang.org/x/crypto v0.56.0 h1:GUh5Ii4J5jtcseSMiRqr1jXCNHoxjeV9Fmekc2oLy6Y=
+golang.org/x/crypto v0.56.0/go.mod h1:OMW5y6CY9l38uPLmxU6l6pwcXp1obtLo3e6gT7gQR2I=
 golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20180807140117-3d87b88a115f/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=