docs: update Coder version in Kubernetes doc (coder#16658)

closes coder#16570 

thanks @Cjkjvfnby !


@matifali I think there is/was an automation, but I'm not sure if it's
been dropped. `kubernetes.md` has:

```md
<!-- autoversion(mainline): "--version [version]" -->
...
<!-- autoversion(stable): "--version [version]" -->
```

~additionally, I removed the `## Prerequisites` section from
`kubernetes-logs.md` because if it's only a requirement for Coder
versions earlier than 0.28.0, it's probably more confusing than useful
to the majority of readers.~

---------

Co-authored-by: M Atif Ali <atif@coder.com>

Author: EdwardAngert

docs/install/kubernetes.md

@@ -129,7 +129,7 @@ We support two release channels: mainline and stable - read the
   helm install coder coder-v2/coder \
       --namespace coder \
       --values values.yaml \
-      --version 2.18.0
+      --version 2.19.0
   ```
 
 - **Stable** Coder release:
@@ -140,7 +140,7 @@ We support two release channels: mainline and stable - read the
   helm install coder coder-v2/coder \
       --namespace coder \
       --values values.yaml \
-      --version 2.17.2
+      --version 2.18.5
   ```
 
 You can watch Coder start up by running `kubectl get pods -n coder`. Once Coder

docs/install/releases.md

@@ -10,7 +10,7 @@ deployment.
 ## Release channels
 
 We support two release channels:
-[mainline](https://github.com/coder/coder/releases/tag/v2.16.0) for the bleeding
+[mainline](https://github.com/coder/coder/releases/tag/v2.19.0) for the bleeding
 edge version of Coder and
 [stable](https://github.com/coder/coder/releases/latest) for those with lower
 tolerance for fault. We field our mainline releases publicly for one month
@@ -77,5 +77,4 @@ pages.
 
 v2.18 was promoted to stable on January 7th, 2025.
 
-Effective starting January, 2025 we will skip the January release each year because most of our engineering team is out for the December holiday period.
-We'll return to our regular release cadence on February 4th.
+As of January, 2025 we skip the January release each year because most of our engineering team is out for the December holiday period.