Update GNU compiler source URLs to use ftpmirror.gnu.org

Change all source URLs from ftp.gnu.org to ftpmirror.gnu.org for improved
mirror availability and reliability when downloading GCC, GMP, MPC, and MPFR
sources for GNU compiler families 12-15.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>
Signed-off-by: Adrian Reber <[email protected]>
(cherry picked from commit e237937)

Author: adrianreber

components/compiler-families/gnu-compilers/SPECS/gnu-compilers.spec

@@ -47,25 +47,25 @@
 %global gnu_version %{gnu15_version}
 %endif
 
-Source0:   https://ftp.gnu.org/gnu/gcc/gcc-%{gnu12_version}/gcc-%{gnu12_version}.tar.xz
-Source1:   https://ftp.gnu.org/gnu/gmp/gmp-%{gnu12_gmp_version}.tar.bz2
-Source2:   https://ftp.gnu.org/gnu/mpc/mpc-%{gnu12_mpc_version}.tar.gz
-Source3:   https://ftp.gnu.org/gnu/mpfr/mpfr-%{gnu12_mpfr_version}.tar.gz
-
-Source4:   https://ftp.gnu.org/gnu/gcc/gcc-%{gnu13_version}/gcc-%{gnu13_version}.tar.xz
-Source5:   https://ftp.gnu.org/gnu/gmp/gmp-%{gnu13_gmp_version}.tar.bz2
-Source6:   https://ftp.gnu.org/gnu/mpc/mpc-%{gnu13_mpc_version}.tar.gz
-Source7:   https://ftp.gnu.org/gnu/mpfr/mpfr-%{gnu13_mpfr_version}.tar.gz
-
-Source8:   https://ftp.gnu.org/gnu/gcc/gcc-%{gnu14_version}/gcc-%{gnu14_version}.tar.xz
-Source9:   https://ftp.gnu.org/gnu/gmp/gmp-%{gnu14_gmp_version}.tar.bz2
-Source10:   https://ftp.gnu.org/gnu/mpc/mpc-%{gnu14_mpc_version}.tar.gz
-Source11:   https://ftp.gnu.org/gnu/mpfr/mpfr-%{gnu14_mpfr_version}.tar.gz
-
-Source12:   https://ftp.gnu.org/gnu/gcc/gcc-%{gnu15_version}/gcc-%{gnu15_version}.tar.xz
-Source13:   https://ftp.gnu.org/gnu/gmp/gmp-%{gnu15_gmp_version}.tar.bz2
-Source14:   https://ftp.gnu.org/gnu/mpc/mpc-%{gnu15_mpc_version}.tar.gz
-Source15:   https://ftp.gnu.org/gnu/mpfr/mpfr-%{gnu15_mpfr_version}.tar.gz
+Source0:   https://ftpmirror.gnu.org/gnu/gcc/gcc-%{gnu12_version}/gcc-%{gnu12_version}.tar.xz
+Source1:   https://ftpmirror.gnu.org/gnu/gmp/gmp-%{gnu12_gmp_version}.tar.bz2
+Source2:   https://ftpmirror.gnu.org/gnu/mpc/mpc-%{gnu12_mpc_version}.tar.gz
+Source3:   https://ftpmirror.gnu.org/gnu/mpfr/mpfr-%{gnu12_mpfr_version}.tar.gz
+
+Source4:   https://ftpmirror.gnu.org/gnu/gcc/gcc-%{gnu13_version}/gcc-%{gnu13_version}.tar.xz
+Source5:   https://ftpmirror.gnu.org/gnu/gmp/gmp-%{gnu13_gmp_version}.tar.bz2
+Source6:   https://ftpmirror.gnu.org/gnu/mpc/mpc-%{gnu13_mpc_version}.tar.gz
+Source7:   https://ftpmirror.gnu.org/gnu/mpfr/mpfr-%{gnu13_mpfr_version}.tar.gz
+
+Source8:   https://ftpmirror.gnu.org/gnu/gcc/gcc-%{gnu14_version}/gcc-%{gnu14_version}.tar.xz
+Source9:   https://ftpmirror.gnu.org/gnu/gmp/gmp-%{gnu14_gmp_version}.tar.bz2
+Source10:   https://ftpmirror.gnu.org/gnu/mpc/mpc-%{gnu14_mpc_version}.tar.gz
+Source11:   https://ftpmirror.gnu.org/gnu/mpfr/mpfr-%{gnu14_mpfr_version}.tar.gz
+
+Source12:   https://ftpmirror.gnu.org/gnu/gcc/gcc-%{gnu15_version}/gcc-%{gnu15_version}.tar.xz
+Source13:   https://ftpmirror.gnu.org/gnu/gmp/gmp-%{gnu15_gmp_version}.tar.bz2
+Source14:   https://ftpmirror.gnu.org/gnu/mpc/mpc-%{gnu15_mpc_version}.tar.gz
+Source15:   https://ftpmirror.gnu.org/gnu/mpfr/mpfr-%{gnu15_mpfr_version}.tar.gz
 
 %global pname %{gnu_major_ver}-compilers