docs: Remove "beta" from two more places

These files are safe to edit by hand, so let's get these changes
into the MR too.

GitLab.Extension/source.extension.vsixmanifest

@@ -3,7 +3,7 @@
   <Metadata>
     <Identity Id="gitlab_visual_studio_extension.383ce117-fc49-41d0-8a35-34b9098a0368" Version="0.32.0" Language="en-US" Publisher="GitLab" />
     <DisplayName>GitLab</DisplayName>
-    <Description xml:space="preserve">GitLab Extension for Visual Studio (Beta)</Description>
+    <Description xml:space="preserve">GitLab Extension for Visual Studio</Description>
     <MoreInfo>https://gitlab.com/gitlab-org/editor-extensions/gitlab-visual-studio-extension</MoreInfo>
     <Icon>gitlab-logo.png</Icon>
   </Metadata>
@@ -26,4 +26,4 @@
     <Asset Type="Microsoft.VisualStudio.VsPackage" d:Source="Project" d:ProjectName="%CurrentProject%" Path="|%CurrentProject%;PkgdefProjectOutputGroup|" />
     <Asset Type="Microsoft.VisualStudio.MefComponent" d:Source="Project" d:ProjectName="%CurrentProject%" Path="|%CurrentProject%|" />
   </Assets>
-</PackageManifest>
\ No newline at end of file
+</PackageManifest>

README.md

-# <img src="https://gitlab.com/gitlab-org/editor-extensions/gitlab-visual-studio-extension/-/raw/18c5fd65285b4c2ae30356e81105854ee7ef5213/GitLab.Extension/gitlab-logo.png" width="64" align="center" /> [GitLab Extension for Visual Studio IDE](https://gitlab.com/gitlab-org/editor-extensions/gitlab-visual-studio-extension) ([Beta](https://docs.gitlab.com/ee/policy/experiment-beta-support.html#beta))
+# <img src="https://gitlab.com/gitlab-org/editor-extensions/gitlab-visual-studio-extension/-/raw/18c5fd65285b4c2ae30356e81105854ee7ef5213/GitLab.Extension/gitlab-logo.png" width="64" align="center" /> [GitLab Extension for Visual Studio IDE](https://gitlab.com/gitlab-org/editor-extensions/gitlab-visual-studio-extension)
 
 This is the GitLab extension for Visual Studio (Community, Pro, and Enterprise).
 It is not the [extension for Visual Studio Code](https://marketplace.visualstudio.com/items?itemName=GitLab.gitlab-workflow).