gh-39915: update lcalc to version 2.1.0
    
a long-awaited update to 2.1.0, crucial to supporting Apple's clang 17.
Will fix #39897

### 📝 Checklist

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- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation and checked the documentation
preview.

### ⌛ Dependencies

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URL: #39915
Reported by: Dima Pasechnik
Reviewer(s): Benjamin Hackl

Author: Release Manager

build/pkgs/lcalc/checksums.ini

@@ -1,4 +1,4 @@
 tarball=lcalc-VERSION.tar.xz
-sha1=dacf9ab672136edc2af5fe9adb7b0ced1e63eeff
-sha256=d780c385579cc6ee45fa27ccd2d3a3c4157fbb5ef8cd1b8951d1028bbc64c035
-upstream_url=https://gitlab.com/sagemath/lcalc/uploads/25f029f3c02fcb6c3174972e0ac0e192/lcalc-VERSION.tar.xz
+sha1=1b4cd157fdf4a4fd3d34f794a372a9a924f7a092
+sha256=eca4f7de5f1129a9cec2cd2f012a8362c8489e746f07adae3229dd8eb2541f79
+upstream_url=https://gitlab.com/-/project/12934202/uploads/679cb360a06a713233876cd6fa0ba2fa/lcalc-VERSION.tar.xz

build/pkgs/lcalc/package-version.txt

@@ -1 +1 @@
-2.0.5
+2.1.0