base-files/oldstable 11.1+deb11u11 amd64 [upgradable from: 11.1+deb11u10]
bind9-dnsutils/oldstable 1:9.16.50-1~deb11u2 amd64 [upgradable from: 1:9.16.50-1~deb11u1]
bind9-host/oldstable 1:9.16.50-1~deb11u2 amd64 [upgradable from: 1:9.16.50-1~deb11u1]
bind9-libs/oldstable 1:9.16.50-1~deb11u2 amd64 [upgradable from: 1:9.16.50-1~deb11u1]
bluez-obexd/oldstable-security 5.55-3.1+deb11u2 amd64 [upgradable from: 5.55-3.1+deb11u1]
bluez/oldstable-security 5.55-3.1+deb11u2 amd64 [upgradable from: 5.55-3.1+deb11u1]
containerd.io/bullseye 1.7.22-1 amd64 [upgradable from: 1.6.28-1]
cups-client/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
cups-common/oldstable 2.3.3op2-3+deb11u8 all [upgradable from: 2.3.3op2-3+deb11u6]
cups-core-drivers/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
cups-daemon/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
cups-ipp-utils/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
cups-ppdc/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
cups-server-common/oldstable 2.3.3op2-3+deb11u8 all [upgradable from: 2.3.3op2-3+deb11u6]
cups/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
curl/oldstable 7.74.0-1.3+deb11u13 amd64 [upgradable from: 7.74.0-1.3+deb11u12]
docker-buildx-plugin/bullseye 0.17.1-1~debian.11~bullseye amd64 [upgradable from: 0.12.1-1~debian.11~bullseye]
docker-ce-cli/bullseye 5:27.3.1-1~debian.11~bullseye amd64 [upgradable from: 5:25.0.3-1~debian.11~bullseye]
docker-ce-rootless-extras/bullseye 5:27.3.1-1~debian.11~bullseye amd64 [upgradable from: 5:25.0.3-1~debian.11~bullseye]
docker-ce/bullseye 5:27.3.1-1~debian.11~bullseye amd64 [upgradable from: 5:25.0.3-1~debian.11~bullseye]
docker-compose-plugin/bullseye 2.29.7-1~debian.11~bullseye amd64 [upgradable from: 2.24.5-1~debian.11~bullseye]
exfatprogs/oldstable-security 1.1.0-1+deb11u1 amd64 [upgradable from: 1.1.0-1]
firefox-esr/oldstable-security 115.15.0esr-1~deb11u1 amd64 [upgradable from: 115.14.0esr-1~deb11u1]
gir1.2-gtk-3.0/oldstable 3.24.24-4+deb11u4 amd64 [upgradable from: 3.24.24-4+deb11u3]
gir1.2-javascriptcoregtk-4.0/oldstable-security 2.44.3-1~deb11u1 amd64 [upgradable from: 2.44.2-1~deb11u1]
gir1.2-webkit2-4.0/oldstable-security 2.44.3-1~deb11u1 amd64 [upgradable from: 2.44.2-1~deb11u1]
gtk-update-icon-cache/oldstable 3.24.24-4+deb11u4 amd64 [upgradable from: 3.24.24-4+deb11u3]
gtk2-engines-pixbuf/oldstable 2.24.33-2+deb11u1 amd64 [upgradable from: 2.24.33-2]
intel-microcode/oldstable 3.20240813.1~deb11u1 amd64 [upgradable from: 3.20240514.1~deb11u1]
libaom0/oldstable-security 1.0.0.errata1-3+deb11u2 amd64 [upgradable from: 1.0.0.errata1-3+deb11u1]
libbluetooth3/oldstable-security 5.55-3.1+deb11u2 amd64 [upgradable from: 5.55-3.1+deb11u1]
libc-bin/testing 2.40-2 amd64 [upgradable from: 2.38-12]
libc-l10n/testing 2.40-2 all [upgradable from: 2.38-12]
libc6/testing 2.40-2 amd64 [upgradable from: 2.38-12]
libcups2/oldstable 2.3.3op2-3+deb11u8 amd64 [upgradable from: 2.3.3op2-3+deb11u6]
libcurl3-gnutls/oldstable 7.74.0-1.3+deb11u13 amd64 [upgradable from: 7.74.0-1.3+deb11u12]
libcurl4/oldstable 7.74.0-1.3+deb11u13 amd64 [upgradable from: 7.74.0-1.3+deb11u12]
libexpat1/oldstable-security 2.2.10-2+deb11u6 amd64 [upgradable from: 2.2.10-2+deb11u5]
libgail-3-0/oldstable 3.24.24-4+deb11u4 amd64 [upgradable from: 3.24.24-4+deb11u3]
libgail-common/oldstable 2.24.33-2+deb11u1 amd64 [upgradable from: 2.24.33-2]
libgail18/oldstable 2.24.33-2+deb11u1 amd64 [upgradable from: 2.24.33-2]
libgnutls30/oldstable-security 3.7.1-5+deb11u6 amd64 [upgradable from: 3.7.1-5+deb11u5]
libgtk-3-0/oldstable 3.24.24-4+deb11u4 amd64 [upgradable from: 3.24.24-4+deb11u3]
libgtk-3-bin/oldstable 3.24.24-4+deb11u4 amd64 [upgradable from: 3.24.24-4+deb11u3]
libgtk-3-common/oldstable 3.24.24-4+deb11u4 all [upgradable from: 3.24.24-4+deb11u3]
libgtk2.0-0/oldstable 2.24.33-2+deb11u1 amd64 [upgradable from: 2.24.33-2]
libgtk2.0-bin/oldstable 2.24.33-2+deb11u1 amd64 [upgradable from: 2.24.33-2]
libgtk2.0-common/oldstable 2.24.33-2+deb11u1 all [upgradable from: 2.24.33-2]
libjavascriptcoregtk-4.0-18/oldstable-security 2.44.3-1~deb11u1 amd64 [upgradable from: 2.44.2-1~deb11u1]
libnss-myhostname/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
libnss-systemd/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
libpam-systemd/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
libsystemd0/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
libwebkit2gtk-4.0-37/oldstable-security 2.44.3-1~deb11u1 amd64 [upgradable from: 2.44.2-1~deb11u1]
libxml2/oldstable-security 2.9.10+dfsg-6.7+deb11u5 amd64 [upgradable from: 2.9.10+dfsg-6.7+deb11u4]
locales/testing 2.40-2 all [upgradable from: 2.38-12]
systemd-sysv/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
systemd-timesyncd/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
systemd/oldstable-security 247.3-7+deb11u6 amd64 [upgradable from: 247.3-7+deb11u5]
xorgxrdp/testing 1:0.9.19-1 amd64 [upgradable from: 1:0.2.17-1]

Remove everything after /in each line.
I want output like following:
base-files bind9-dnsutils bind9-host bind9-libs...