Updated dependencies to fix govulncheck

[applejag]

Changes:

• Ran go get -u
• Updated version in go.mod from 1.21.1 to 1.21.3

Fixes the following vulnerabilities:

$ govulncheck ./...
Using go1.21.1 and [email protected] with vulnerability data from https://vuln.go.dev (last modified 2023-10-12 16:23:05 +0000 UTC).

Scanning your code and 313 packages across 47 dependent modules for known vulnerabilities...

Vulnerability #1: GO-2023-2102
    HTTP/2 rapid reset can cause excessive work in net/http
  More info: https://pkg.go.dev/vuln/GO-2023-2102
  Module: golang.org/x/net
    Found in: golang.org/x/[email protected]
    Fixed in: golang.org/x/[email protected]
    Example traces found:
      #1: pkg/server/server.go:163:21: server.HTTPServer.Serve calls gin.Engine.Run, which eventually calls http2.Server.ServeConn

  Standard library
    Found in: net/[email protected]
    Fixed in: net/[email protected]
    Example traces found:
      #1: pkg/server/server.go:163:21: server.HTTPServer.Serve calls gin.Engine.Run, which calls http.ListenAndServe

Your code is affected by 1 vulnerability from 1 module and the Go standard library.

Share feedback at https://go.dev/s/govulncheck-feedback.