Fix meta description clash (#41913)

Two Workload Identity pages have the same meta description, which can be
harmful for SEO. This change gives each page a different meta
description.

docs/pages/machine-id/workload-identity.mdx

@@ -1,6 +1,6 @@
 ---
 title: Workload Identity
-description: Teleport's Workload Identity for SPIFFE
+description: Describes Teleport Workload Identity, which issues flexible, short-lived identities to secure workload-to-workload communications.
 ---
 
 <Admonition type="tip" title="Preview">
@@ -152,4 +152,4 @@ Teleport's Workload Identity currently only supports issuing X.509-SVIDs.
 ### Other resources
 
 - [SPIFFE Specification](https://github.com/spiffe/spiffe/blob/main/standards/SPIFFE.md): The official SPIFFE specification. Useful for understanding the SPIFFE ID and SVID formats.
-- [Solving The Bottom Turtle](https://spiffe.io/pdf/Solving-the-bottom-turtle-SPIFFE-SPIRE-Book.pdf): A book covering the fundamentals and details of SPIFFE.
+- [Solving The Bottom Turtle](https://spiffe.io/pdf/Solving-the-bottom-turtle-SPIFFE-SPIRE-Book.pdf): A book covering the fundamentals and details of SPIFFE.

docs/pages/machine-id/workload-identity/best-practices.mdx

@@ -1,6 +1,6 @@
 ---
 title: Best Practices for Teleport Workload Identity
-description: Teleport's Workload Identity for SPIFFE
+description: Answers common questions and describes best practices for using Teleport Workload Identity in production.
 ---
 
 This page covers common questions and best practices for using Teleport's