chore(feature-flags): fix formatting issue (#24141)

The extra period in this text block changes the generated feature flag on every build. It looks like it was updated accidentally after the generated one was built and committed with the extra period.

Closes #<issue number here>.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/cx-api/lib/features.ts

@@ -634,12 +634,12 @@ export const FLAGS: Record<string, FlagInfo> = {
     type: FlagType.BugFix,
     summary: 'Use unique resource name for Database Proxy',
     detailsMd: `
-      If this flag is not set, the default behavior for \`DatabaseProxy\` is 
-      to use \`id\` of the constructor for \`dbProxyName\` when it's not specified in the argument..
+      If this flag is not set, the default behavior for \`DatabaseProxy\` is
+      to use \`id\` of the constructor for \`dbProxyName\` when it's not specified in the argument.
       In this case, users can't deploy \`DatabaseProxy\`s that have the same \`id\` in the same region.
-      
+
       If this flag is set, the default behavior is to use unique resource names for each \`DatabaseProxy\`.
-      
+
       This is a feature flag as the old behavior was technically incorrect, but users may have come to depend on it.
     `,
     introducedIn: { v2: 'V2NEXT' },