TPath*Browse: set QPushButton minimum height to 32

The Qt docs state:
    Note: On macOS when a push button's width becomes smaller than 50 or
    its height becomes smaller than 30, the button's corners are changed
    from round to square.
    https://doc.qt.io/qt-5/qpushbutton.html

On macOS 13.6 with Qt 5.15.10, this occurs whenever the height is less
than 32.

(This change will likely be applied to other uses of QPushButton, but
that's outside of the scope of this particular commit.)

lib/forms/TPathComboBrowse.ui

@@ -78,6 +78,12 @@
      </item>
      <item>
       <widget class="QPushButton" name="button">
+       <property name="minimumSize">
+        <size>
+         <width>0</width>
+         <height>32</height>
+        </size>
+       </property>
        <property name="text">
         <string>Browse</string>
        </property>

lib/forms/TPathLineBrowse.ui

@@ -82,6 +82,12 @@
      </item>
      <item>
       <widget class="QPushButton" name="button">
+       <property name="minimumSize">
+        <size>
+         <width>0</width>
+         <height>32</height>
+        </size>
+       </property>
        <property name="text">
         <string>Browse</string>
        </property>