Port former create_tarball into COPR Makefile

This script was removed in #1793; instead of restoring it, instead
implement its functionality directly in the COPR Makefile.

.copr/Makefile

@@ -2,7 +2,49 @@ srpm:
 	dnf -y install git
 	git submodule update --init --recursive
 	cd deployment/fedora-package-x64;                    \
-	./create_tarball.sh;                                 \
+    WORKDIR="$( pwd )"; \
+    VERSION="$( sed -ne '/^Version:/s/.*  *//p' "${WORKDIR}"/pkg-src/jellyfin.spec )"; \
+    package_temporary_dir="${WORKDIR}/pkg-dist-tmp"; \
+    pkg_src_dir="${WORKDIR}/pkg-src"; \
+    GNU_TAR=1; \
+    tar \
+    --transform "s,^\.,jellyfin-${VERSION}," \
+    --exclude='.git*' \
+    --exclude='**/.git' \
+    --exclude='**/.hg' \
+    --exclude='**/.vs' \
+    --exclude='**/.vscode' \
+    --exclude='deployment' \
+    --exclude='**/bin' \
+    --exclude='**/obj' \
+    --exclude='**/.nuget' \
+    --exclude='*.deb' \
+    --exclude='*.rpm' \
+    -czf "${SOURCE_DIR}/SOURCES/pkg-src/jellyfin-${VERSION}.tar.gz" \
+    -C ${SOURCE_DIR} ./ || GNU_TAR=0; \
+    if [ $GNU_TAR -eq 0 ]; then
+        package_temporary_dir="$( mktemp -d )"; \
+        mkdir -p "${package_temporary_dir}/jellyfin"; \
+        tar \
+        --exclude='.git*' \
+        --exclude='**/.git' \
+        --exclude='**/.hg' \
+        --exclude='**/.vs' \
+        --exclude='**/.vscode' \
+        --exclude='deployment' \
+        --exclude='**/bin' \
+        --exclude='**/obj' \
+        --exclude='**/.nuget' \
+        --exclude='*.deb' \
+        --exclude='*.rpm' \
+        -czf "${package_temporary_dir}/jellyfin/jellyfin-${VERSION}.tar.gz" \
+        -C ${SOURCE_DIR} ./; \
+        mkdir -p "${package_temporary_dir}/jellyfin-${VERSION}"; \
+        tar -xzf "${package_temporary_dir}/jellyfin/jellyfin-${VERSION}.tar.gz" -C "${package_temporary_dir}/jellyfin-${VERSION}"; \
+        rm -f "${package_temporary_dir}/jellyfin/jellyfin-${VERSION}.tar.gz"; \
+        tar -czf "${SOURCE_DIR}/SOURCES/pkg-src/jellyfin-${VERSION}.tar.gz" -C "${package_temporary_dir}" "jellyfin-${VERSION}"; \
+        rm -rf ${package_temporary_dir}; \
+    fi; \
 	rpmbuild -bs pkg-src/jellyfin.spec                   \
 	         --define "_sourcedir $$PWD/pkg-src/"        \
 		 --define "_srcrpmdir $(outdir)"