gh-35570: 4ti2: Update to 1.6.10, fixes `egrep` issue, adds GCC 13 support
    
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### 📚 Description

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Just released: https://github.com/4ti2/4ti2/releases/tag/Release_1_6_10,
with portability fixes, in particular for:
- #35092
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Resolves #30344
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URL: #35570
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

Author: Release Manager

build/pkgs/4ti2/checksums.ini

@@ -1,4 +1,5 @@
 tarball=4ti2-VERSION.tar.gz
-sha1=9a9a6913bcd52b667355a7df7fa954ca101054cb
-md5=90def0d6b01a0247e439356777467497
-cksum=439147307
+sha1=3d41f30ea3ef94c293eae30c087494269fc1a6b9
+md5=1215872325ddfc561865ecb22b2bccb2
+cksum=2439180289
+upstream_url=https://github.com/4ti2/4ti2/releases/download/Release_1_6_10/4ti2-1.6.10.tar.gz

build/pkgs/4ti2/package-version.txt

@@ -1 +1 @@
-1.6.7.p0
+1.6.10