Ensure link is CTRL-clickable

Some UIs automatically linkify the link. However, a trailing `.` is included in the link.
This ensures the link is separated by whitespace.

Author: eps1lon

src/__tests__/render.js

@@ -234,7 +234,7 @@ describe('render API', () => {
     expect(() => {
       render(<div />, {legacyRoot: true})
     }).toThrowErrorMatchingInlineSnapshot(
-      `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, and you need help with upgrading your app, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide.`,
+      `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide for upgrade instructions.`,
     )
   })
 
@@ -259,7 +259,7 @@ describe('render API', () => {
     expect(() => {
       render(ui, {container, hydrate: true, legacyRoot: true})
     }).toThrowErrorMatchingInlineSnapshot(
-      `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, and you need help with upgrading your app, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide.`,
+      `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide for upgrade instructions.`,
     )
   })
 })

src/__tests__/renderHook.js

@@ -108,6 +108,6 @@ testGateReact19('legacyRoot throws', () => {
       },
     ).result
   }).toThrowErrorMatchingInlineSnapshot(
-    `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, and you need help with upgrading your app, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide.`,
+    `\`legacyRoot: true\` is not supported in this version of React. If your app runs React 19 or later, you should remove this flag. If your app runs React 18 or earlier, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide for upgrade instructions.`,
   )
 })

src/pure.js

@@ -211,7 +211,7 @@ function render(
     const error = new Error(
       '`legacyRoot: true` is not supported in this version of React. ' +
         'If your app runs React 19 or later, you should remove this flag. ' +
-        'If your app runs React 18 or earlier, and you need help with upgrading your app, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide.',
+        'If your app runs React 18 or earlier, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide for upgrade instructions.',
     )
     Error.captureStackTrace(error, render)
     throw error
@@ -278,7 +278,7 @@ function renderHook(renderCallback, options = {}) {
     const error = new Error(
       '`legacyRoot: true` is not supported in this version of React. ' +
         'If your app runs React 19 or later, you should remove this flag. ' +
-        'If your app runs React 18 or earlier, and you need help with upgrading your app, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide.',
+        'If your app runs React 18 or earlier, visit https://react.dev/blog/2022/03/08/react-18-upgrade-guide for upgrade instructions.',
     )
     Error.captureStackTrace(error, renderHook)
     throw error