Clean up some spell images.

This specific set is erroneously used as rune images in current trunk server (v1.75.0-1269), so we can reduce bandwidth by having these be redone.

ChangeLog.rtro

@@ -1,6 +1,16 @@
 ------------------------
 Changes for top of trunk
 ------------------------
+2023-08-28 Daniel Hawkins
+	* spell/Rune/spell_firetrap.rtro.111.png,
+	  spell/Rune/spell_glyph.rtro.111.png,
+	  spell/Rune/spell_magic_rune.rtro.111.png,
+	  spell/Rune/spell_pentagram.rtro.111.png,
+	  spell/Rune/spell_sigil.rtro.111.png: Rederive from base images, sticking to XPM palette.
+	    These ones were done specifically because there's a bug that seems to cause their images
+	    to be used as runes in trunk (1.75.0-1269). This reduces bandwidth when that occurs for
+	    a player using the retro face set.
+
 2023-08-21 Daniel Hawkins
 	* misc/Container/quiver_arrow.rtro.111.png,
 	  misc/Container/quiver_bolt.rtro.111.png: Make visually distinct from regular quivers.