Update zoneinfo files to 2026a (#339)

Moldova (Europe/Chisinau, and its link Europe/Tiraspol) has
actually used EU transition times since 2022, so it shifts
into and out of daylight time at 03:00 and 04:00 respectively,
not 02:00 and 03:00.

zic no longer generates a no-op transition when simultaneous
Rule and Zone changes cancel each other out, which affects
Asia/Tbilisi.

Author: devbww

src/tzfile.h

@@ -17,16 +17,8 @@
 ** Thank you!
 */
 
-/*
-** Information about time zone files.
-*/
-
-#ifndef TZDEFRULES
-# define TZDEFRULES "posixrules"
-#endif /* !defined TZDEFRULES */
-
-
-/* See Internet RFC 9636 for more details about the following format.  */
+/* Information about time zone files.
+   See Internet RFC 9636 for more details about the following format.  */
 
 /*
 ** Each file begins with. . .
@@ -97,23 +89,25 @@ struct tzhead {
 */
 
 #ifndef TZ_MAX_TIMES
-/* This must be at least 242 for Europe/London with 'zic -b fat'.  */
+/* The following limit applies to localtime.c; zic has no such limit.
+   The limit must be at least 310 for Asia/Hebron with 'zic -b fat'.  */
 # define TZ_MAX_TIMES 2000
 #endif /* !defined TZ_MAX_TIMES */
 
 #ifndef TZ_MAX_TYPES
 /* This must be at least 18 for Europe/Vilnius with 'zic -b fat'.  */
-# define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
+# define TZ_MAX_TYPES 256 /* Limited to 256 by Internet RFC 9636.  */
 #endif /* !defined TZ_MAX_TYPES */
 
 #ifndef TZ_MAX_CHARS
 /* This must be at least 40 for America/Anchorage.  */
-# define TZ_MAX_CHARS 50	/* Maximum number of abbreviation characters */
-				/* (limited by what unsigned chars can hold) */
+# define TZ_MAX_CHARS 256	/* Maximum number of abbreviation characters */
+				/* (limited to 256 by Internet RFC 9636) */
 #endif /* !defined TZ_MAX_CHARS */
 
 #ifndef TZ_MAX_LEAPS
-/* This must be at least 27 for leap seconds from 1972 through mid-2023.
+/* The following limit applies to localtime.c; zic has no such limit.
+   The limit must be at least 27 for leap seconds from 1972 through mid-2023.
    There's a plan to discontinue leap seconds by 2035.  */
 # define TZ_MAX_LEAPS 50	/* Maximum number of leap second corrections */
 #endif /* !defined TZ_MAX_LEAPS */

testdata/version

@@ -1 +1 @@
-2025c
+2026a

testdata/zoneinfo/Asia/Tbilisi

@@ -166,9 +166,6 @@ XX	+3003+03115	Africa/Cairo	Egypt
 # +02/+03 - EET/EEST (Lebanon DST)
 XX	+3353+03530	Asia/Beirut	Lebanon
 #
-# +02/+03 - EET/EEST (Moldova DST)
-XX	+4700+02850	Europe/Chisinau	Moldova
-#
 # +02/+03 - EET/EEST (Palestine DST)
 XX	+3130+03428	Asia/Gaza	Palestine
 #