Consistently spell "leakproof" without a hyphen.

The overwhelming majority of places already did this, but a small
handful of places had a hyphen.

Yugo Nagata.

Discussion: https://postgr.es/m/CAEZATCXnnuORE2BoGwHw2zbtVvsPOLhbfVmEk9GxRzK%2Bx3OW-Q%40mail.gmail.com

doc/src/sgml/catalogs.sgml

@@ -6040,7 +6040,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        The function has no side effects.  No information about the
        arguments is conveyed except via the return value.  Any function
        that might throw an error depending on the values of its arguments
-       is not leak-proof.
+       is not leakproof.
       </para></entry>
      </row>
 

doc/src/sgml/planstats.sgml

@@ -740,7 +740,7 @@ EXPLAIN (ANALYZE, TIMING OFF, BUFFERS OFF) SELECT * FROM t WHERE a <= 49 AND
    error, in which case this mechanism is invisible in practice.  But if the
    user is reading from a security-barrier view, then the planner might wish
    to check the statistics of an underlying table that is otherwise
-   inaccessible to the user.  In that case, the operator should be leak-proof
+   inaccessible to the user.  In that case, the operator should be leakproof
    or the statistics will not be used.  There is no direct feedback about
    that, except that the plan might be suboptimal.  If one suspects that this
    is the case, one could try running the query as a more privileged user,

doc/src/sgml/rules.sgml

@@ -2162,7 +2162,7 @@ CREATE VIEW phone_number WITH (security_barrier) AS
     <literal>LEAKPROOF</literal> to be pushed down, as they never receive data
     from the view.  In contrast, a function that might throw an error depending
     on the values received as arguments (such as one that throws an error in the
-    event of overflow or division by zero) is not leak-proof, and could provide
+    event of overflow or division by zero) is not leakproof, and could provide
     significant information about the unseen rows if applied before the security
     view's row filters.
 </para>