Helm release is not updated if chart version has changed in skaffold config file

### Expected behavior
The command `skaffold deploy --skip-render` upgrades a release to a new version of a chart if `deploy.helm.releases.[].version` has changed.

### Actual behavior
The command `skaffold deploy --skip-render` does nothing if `deploy.helm.releases.[].version` has changed.

### Information

- Skaffold version: 1.27.0
- Operating system: Windows 10
- Installed via: binary downloaded from GitHub release
- Contents of skaffold.yaml:

```yaml
apiVersion: skaffold/v2beta18
kind: Config
metadata:
name: cloud-platform-k8s
deploy:
helm:
flags:
upgrade:
- --install
releases:
- name: nginx-ingress
namespace: ingress-nginx
createNamespace: true
repo: https://kubernetes.github.io/ingress-nginx
remoteChart: ingress-nginx
version: 3.33.0
valuesFiles:
- controllers/ingress-nginx/values.yaml
wait: true
```

### Steps to reproduce the behavior

1. Use the above skaffold config (valuesFiles may be skipped)
2. `skaffold deploy --skip-render`
3. Verify installed chart version:

```
> helm list --all-namespaces
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
nginx-ingress ingress-nginx 1 2021-06-30 11:17:40.6111103 +0200 CEST deployed ingress-nginx-3.33.0 0.47.0
```

4. Change the `deploy.helm.releases.[].version` to `3.34.0` and repeat step 2 and 3
5. The version is still `3.33.0`

### Deboug output
```
> skaffold deploy --skip-render -v debug
time="2021-06-30T12:19:19+02:00" level=info msg="Skaffold &{Version:v1.27.0 ConfigVersion:skaffold/v2beta18 GitVersion: GitCommit:1f46f249c832bb2a99e3285ad327647c95ff4bb9 BuildDate:2021-06-29T21:40:35Z GoVersion:go1.14.14 Compiler:gc Platform:windows/amd64 User:}"
time="2021-06-30T12:19:19+02:00" level=info msg="Loaded Skaffold defaults from \"C:\\\\Users\\\\user\\\\.skaffold\\\\config\""
time="2021-06-30T12:19:19+02:00" level=debug msg="parsed 1 configs from configuration file C:\\Git\\cloud-platform-k8s\\skaffold.yaml"
time="2021-06-30T12:19:19+02:00" level=debug msg="Defaulting build type to local build"
time="2021-06-30T12:19:19+02:00" level=info msg="Using kubectl context: "
time="2021-06-30T12:19:19+02:00" level=debug msg="Running command: [minikube version --output=json]"
time="2021-06-30T12:19:19+02:00" level=debug msg="setting Docker user agent to skaffold-v1.27.0"
time="2021-06-30T12:19:19+02:00" level=debug msg="Using builder: local"
time="2021-06-30T12:19:19+02:00" level=debug msg="push value not present in NewBuilder, defaulting to true because cluster.PushImages is true"
time="2021-06-30T12:19:19+02:00" level=info msg="build concurrency first set to 0 parsed from *local.Builder[0]"
time="2021-06-30T12:19:19+02:00" level=info msg="final build concurrency value is 0"
time="2021-06-30T12:19:19+02:00" level=debug msg="Running command: [helm version --client]"
time="2021-06-30T12:19:19+02:00" level=debug msg="could not parse date \"\""
time="2021-06-30T12:19:19+02:00" level=debug msg="Command output: [version.BuildInfo{Version:\"v3.5.4\", GitCommit:\"1b5edb69df3d3a08df77c9902dc17af864ff05d1\", GitTreeState:\"clean\", GoVersion:\"go1.15.11\"}\n]"
Tags used in deployment:
time="2021-06-30T12:19:19+02:00" level=debug msg="getting client config for kubeContext: ``"
Starting deploy...
time="2021-06-30T12:19:20+02:00" level=info msg="Deploying with helm v3.5.4 ..."
time="2021-06-30T12:19:20+02:00" level=debug msg="Executing template [...]
time="2021-06-30T12:19:20+02:00" level=debug msg="Running command: [helm --kube-context get all --namespace ingress-nginx nginx-ingress]"
time="2021-06-30T12:19:21+02:00" level=info msg="Release nginx-ingress not upgraded as it is remote..."
time="2021-06-30T12:19:21+02:00" level=info msg="Deploy completed in 969.6978ms"
Waiting for deployments to stabilize...
time="2021-06-30T12:19:21+02:00" level=debug msg="getting client config for kubeContext: ``"
Deployments stabilized in 550.399ms

time="2021-06-30T12:19:22+02:00" level=debug msg="exporting metrics"
time="2021-06-30T12:19:23+02:00" level=debug msg="metrics uploading complete in 967.2939ms"
```