Fix typo in compose pull documentation

There was an invalid character between the two backticks at the end of the last snippet, causing the styling to break on the online documentation.

Signed-off-by: Emmanuel Nuiro <[email protected]>

docs/reference/compose_pull.md

@@ -61,4 +61,4 @@ $ docker compose pull db
    ⠹ f63c47038e66 Waiting                                                  9.3s
    ⠹ 77a0c198cde5 Waiting                                                  9.3s
    ⠹ c8752d5b785c Waiting                                                  9.3s
-``̀`
+```