Rename travis-ci/ directory to ci/

We are no longer using Travis. As such, we should move away from a lot
of CI functionality located in a folder called travis-ci/. This change
renames the travis-ci/ directory to the more generic ci/.
To preserve backwards compatibility until all "consumers" have
transitioned, we add a symbolic link called travis-ci back. It will be
removed in the near term future.

Signed-off-by: Daniel Müller <deso@posteo.net>

ci/vmtest/configs/ALLOWLIST-5.5.0

@@ -0,0 +1,55 @@
+# attach_probe
+autoload
+bpf_verif_scale
+cgroup_attach_autodetach
+cgroup_attach_override
+core_autosize
+core_extern
+core_read_macros
+core_reloc
+core_retro
+cpu_mask
+endian
+get_branch_snapshot
+get_stackid_cannot_attach
+global_data
+global_data_init
+global_func_args
+hashmap
+l4lb_all
+legacy_printk
+linked_funcs
+linked_maps
+map_lock
+obj_name
+perf_buffer
+perf_event_stackmap
+pinning
+pkt_md_access
+probe_user
+queue_stack_map
+raw_tp_writable_reject_nbd_invalid
+raw_tp_writable_test_run
+rdonly_maps
+section_names
+signal_pending
+skeleton
+sockmap_ktls
+sockopt
+sockopt_inherit
+sockopt_multi
+spinlock
+stacktrace_map
+stacktrace_map_raw_tp
+static_linked
+task_fd_query_rawtp
+task_fd_query_tp
+tc_bpf
+tcp_estats
+tcp_rtt
+tp_attach_query
+usdt/urand_pid_attach
+xdp
+xdp_info
+xdp_noinline
+xdp_perf