function2: upgrade 4.2.4+git -> 4.2.5

The recipe was pinned to the 4.2.4 tag but carried a +git PV suffix; 4.2.5 is
a real tagged release so the suffix is dropped. Upstream release notes list
three changes: support for uses-allocator construction, with std::uses_allocator
specialized for all function types (PR #62); std::aligned_storage_t is no longer
used, since it is deprecated in C++23 (PR #67); and an AppVeyor CI fix (PR #68).
Header-only library with no API break.

AI-Generated: Uses Claude Code
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-oe/recipes-support/function2/function2_4.2.5.bb

@@ -3,8 +3,7 @@ DESCRIPTION = "Provides improved implementations of std::function."
 HOMEPAGE = "https://naios.github.io/function2"
 LICENSE = "BSL-1.0"
 LIC_FILES_CHKSUM = "file://LICENSE.txt;md5=e4224ccaecb14d942c71d31bef20d78c"
-SRCREV = "a354bd093d2b6e50c9325dbce84d20b4e77aabc6"
-PV .= "+git"
+SRCREV = "496c20fede5378190fff471fcd7ee3d8705e5096"
 
 SRC_URI += "gitsm://github.com/Naios/function2;branch=master;protocol=https"