Bump github.com/hashicorp/go-retryablehttp to address CVE-2024-6104

Before change
```
~>  govulncheck ./...
=== Symbol Results ===

Vulnerability #1: GO-2024-2947
    Leak of sensitive information to log files in
    github.com/hashicorp/go-retryablehttp
  More info: https://pkg.go.dev/vuln/GO-2024-2947
  Module: github.com/hashicorp/go-retryablehttp
    Found in: github.com/hashicorp/go-retryablehttp@v0.7.6
    Fixed in: github.com/hashicorp/go-retryablehttp@v0.7.7
    Example traces found:
      #1: hcl2template/function/vault.go:30:30: function.init calls template.Vault, which eventually calls retryablehttp.Client.Do

Your code is affected by 1 vulnerability from 1 module.
```

After Change
```
~>  govulncheck ./...
No vulnerabilities found.
```

go.mod

@@ -124,7 +124,7 @@ require (
 	github.com/hashicorp/go-getter/s3/v2 v2.2.2 // indirect
 	github.com/hashicorp/go-hclog v1.6.3 // indirect
 	github.com/hashicorp/go-immutable-radix v1.3.1 // indirect
-	github.com/hashicorp/go-retryablehttp v0.7.6 // indirect
+	github.com/hashicorp/go-retryablehttp v0.7.7 // indirect
 	github.com/hashicorp/go-rootcerts v1.0.2 // indirect
 	github.com/hashicorp/go-safetemp v1.0.0 // indirect
 	github.com/hashicorp/go-secure-stdlib/parseutil v0.1.6 // indirect

go.sum

@@ -269,8 +269,8 @@ github.com/hashicorp/go-multierror v1.1.0/go.mod h1:spPvp8C1qA32ftKqdAHm4hHTbPw+
 github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
 github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/hashicorp/go-retryablehttp v0.5.3/go.mod h1:9B5zBasrRhHXnJnui7y6sL7es7NDiJgTc6Er0maI1Xs=
-github.com/hashicorp/go-retryablehttp v0.7.6 h1:TwRYfx2z2C4cLbXmT8I5PgP/xmuqASDyiVuGYfs9GZM=
-github.com/hashicorp/go-retryablehttp v0.7.6/go.mod h1:pkQpWZeYWskR+D1tR2O5OcBFOxfA7DoAO6xtkuQnHTk=
+github.com/hashicorp/go-retryablehttp v0.7.7 h1:C8hUCYzor8PIfXHa4UrZkU4VvK8o9ISHxT2Q8+VepXU=
+github.com/hashicorp/go-retryablehttp v0.7.7/go.mod h1:pkQpWZeYWskR+D1tR2O5OcBFOxfA7DoAO6xtkuQnHTk=
 github.com/hashicorp/go-rootcerts v1.0.2 h1:jzhAVGtqPKbwpyCPELlgNWhE1znq+qwJtW5Oi2viEzc=
 github.com/hashicorp/go-rootcerts v1.0.2/go.mod h1:pqUvnprVnM5bf7AOirdbb01K4ccR319Vf4pU3K5EGc8=
 github.com/hashicorp/go-safetemp v1.0.0 h1:2HR189eFNrjHQyENnQMMpCiBAsRxzbTMIgBhEyExpmo=