Revert "add const qualifier to the first arg of TextJoin (#5166)"

This reverts commit 4e8d08523f.

src/raylib.h

@@ -1515,7 +1515,7 @@ RLAPI const char *TextFormat(const char *text, ...);
 RLAPI const char *TextSubtext(const char *text, int position, int length);                  // Get a piece of a text string
 RLAPI char *TextReplace(const char *text, const char *replace, const char *by);             // Replace text string (WARNING: memory must be freed!)
 RLAPI char *TextInsert(const char *text, const char *insert, int position);                 // Insert text in a position (WARNING: memory must be freed!)
-RLAPI char *TextJoin(const char **textList, int count, const char *delimiter);              // Join text strings with delimiter
+RLAPI char *TextJoin(char **textList, int count, const char *delimiter);                    // Join text strings with delimiter
 RLAPI char **TextSplit(const char *text, char delimiter, int *count);                       // Split text into multiple strings, using MAX_TEXTSPLIT_COUNT static strings
 RLAPI void TextAppend(char *text, const char *append, int *position);                       // Append text at specific position and move cursor!
 RLAPI int TextFindIndex(const char *text, const char *find);                                // Find first text occurrence within a string, -1 if not found