Remove empty notes column from provider table

The Note column in the cloud access provider table was empty for
all entries and served no purpose. Remove it to simplify the table.

AI-assisted: Claude Code
Signed-off-by: Roger Luethi <luethi@osism.tech>

Author: ideaship

docs/testbed/prerequisites.mdx

@@ -14,19 +14,19 @@ the capabilities for nested virtualization.
 It is not part of this guide to describe the registration with the individual cloud
 providers. Please contact the respective cloud provider for this.
 
-| Provider      | Product            | Profile name    | Note                              |
-|:--------------|:-------------------|:----------------|:----------------------------------|
-| OSISM         | REGIO.cloud        | `regiocloud`    |                                   |
-| Cleura        | Cleura             | `cleura`        |                                   |
-| HuaweiCloud   | HuaweiCloud        | `huaweicloud`   |                                   |
-| OVH           | OVH                | `ovh`           |                                   |
-| T-Systems     | OpenTelekomCloud   | `otc`           |                                   |
-| plusserver    | pluscloud open     | `pluscloudopen` |                                   |
-| plusserver    | pluscloud SCS Test | `gx-scs`        |                                   |
-| noris network | Wavestack          | `wavestack`     |                                   |
-| Cloud&Heat    | Cloud&Heat F1A     | `cah-f1a`       |                                   |
-| exigo         | exigo.cloud        | `exigo`         |                                   |
-| artcodix      | CNDS Cloud         | `artcodix`      |                                   |
+| Provider      | Product            | Profile name    |
+|:--------------|:-------------------|:----------------|
+| OSISM         | REGIO.cloud        | `regiocloud`    |
+| Cleura        | Cleura             | `cleura`        |
+| HuaweiCloud   | HuaweiCloud        | `huaweicloud`   |
+| OVH           | OVH                | `ovh`           |
+| T-Systems     | OpenTelekomCloud   | `otc`           |
+| plusserver    | pluscloud open     | `pluscloudopen` |
+| plusserver    | pluscloud SCS Test | `gx-scs`        |
+| noris network | Wavestack          | `wavestack`     |
+| Cloud&Heat    | Cloud&Heat F1A     | `cah-f1a`       |
+| exigo         | exigo.cloud        | `exigo`         |
+| artcodix      | CNDS Cloud         | `artcodix`      |
 
 For each cloud provider listed in the table, a predefined profile is available in the
 [`terraform/environments`](https://github.com/osism/testbed/tree/main/terraform/environments/)