fix(steps-guix): add cmake bootstrap build and libgit2 cmake-based build steps

steps-guix/cmake-4.2.3/pass1.sh

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_prepare() {
+    default
+}
+
+src_configure() {
+    ./bootstrap \
+        --prefix="${PREFIX}" \
+        --parallel="${JOBS}" \
+        --no-qt-gui \
+        -- \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_USE_OPENSSL=ON \
+        -DCMAKE_INSTALL_LIBDIR="${LIBDIR}"
+}
+
+src_compile() {
+    make "${MAKEJOBS}"
+}
+
+src_install() {
+    make install DESTDIR="${DESTDIR}"
+}

steps-guix/cmake-4.2.3/sources

@@ -0,0 +1 @@
+f https://github.com/Kitware/CMake/releases/download/v4.2.3/cmake-4.2.3.tar.gz 7efaccde8c5a6b2968bad6ce0fe60e19b6e10701a12fce948c2bf79bac8a11e9

steps-guix/libgit2-1.9.2/pass1.sh

@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_prepare() {
+    default
+}
+
+src_configure() {
+    mkdir -p build
+    cd build
+
+    cmake .. \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX="${PREFIX}" \
+        -DCMAKE_INSTALL_LIBDIR="${LIBDIR}" \
+        -DBUILD_SHARED_LIBS=OFF \
+        -DBUILD_TESTS=OFF \
+        -DBUILD_CLI=OFF \
+        -DBUILD_EXAMPLES=OFF \
+        -DUSE_SSH=OFF \
+        -DUSE_HTTPS=OpenSSL \
+        -DUSE_HTTP_PARSER=builtin \
+        -DREGEX_BACKEND=regcomp \
+        -DUSE_BUNDLED_ZLIB=OFF \
+        -DUSE_THREADS=ON
+}
+
+src_compile() {
+    make "${MAKEJOBS}"
+}
+
+src_install() {
+    make install DESTDIR="${DESTDIR}"
+}

steps-guix/libgit2-1.9.2/sources

@@ -0,0 +1 @@
+f https://github.com/libgit2/libgit2/archive/refs/tags/v1.9.2.tar.gz 6f097c82fc06ece4f40539fb17e9d41baf1a5a2fc26b1b8562d21b89bc355fe6 libgit2-1.9.2.tar.gz

steps-guix/manifest

@@ -17,8 +17,8 @@ build: libgpg-error-1.59
 build: libgcrypt-1.12.1
 build: guile-gcrypt-0.5.0
 build: git-2.53.0
-# build: cmake
-# build: libgit
+build: cmake-4.2.3
+build: libgit2-1.9.2
 # build: nettle-3.10.2
 # build: libtasn1-v4.21.0
 # build: p11-kit-0.26.2