DEVEX-20 rpk: add collection of /proc/<RP_PID>/ info to debug bundles

[JFlath]

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https://redpandadata.atlassian.net/browse/DEVEX-20

Backports Required

• [ ] none - not a bug fix
• [ ] none - this is a backport
• [ ] none - issue does not exist in previous branches
• [ ] none - papercut/not impactful enough to backport
• [x] v24.2.x
• [x] v24.1.x
• [ ] v23.3.x

Release Notes

• none

[JFlath]

@r-vasquez I can take the whitespace that lint is complaining about out by hand, but curious if there's a better way? go fmt doesn't seem to care about it, and running the new make ready gives a number of unrelated errors, as well as one that's a false positive for this change:

installing golangci-lint
golangci-lint run
pkg/tuners/disk/block_device.go:28:6: type `blockDevice` is unused (unused)
type blockDevice struct {
     ^
pkg/tuners/disk/block_device.go:34:23: func `(*blockDevice).Syspath` is unused (unused)
func (d *blockDevice) Syspath() string {
                      ^
pkg/tuners/disk/block_device.go:38:23: func `(*blockDevice).Devnode` is unused (unused)
func (d *blockDevice) Devnode() string {
                      ^
pkg/tuners/disk/block_device.go:42:23: func `(*blockDevice).Parent` is unused (unused)
func (d *blockDevice) Parent() BlockDevice {
                      ^
pkg/tuners/disk/block_device.go:46:6: func `deviceFromSystemPath` is unused (unused)
func deviceFromSystemPath(syspath string, fs afero.Fs) (BlockDevice, error) {
     ^
pkg/tuners/disk/block_device.go:73:6: func `parseUeventFile` is unused (unused)
func parseUeventFile(lines []string) (map[string]string, error) {
     ^
pkg/cli/debug/bundle/bundle.go:209:6: func `getRedpandaPID` is unused (unused)
func getRedpandaPID(fs afero.Fs) int {
     ^
make: *** [run_linter] Error 1

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/56349#01927bf2-e0b9-4834-a861-f573a0464072 ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/56349#01927bf2-e0b1-44a1-b68c-4bdb568776d5 ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/56349#01927bf2-e0b4-4d8c-90f2-1d4aeae8f677

[vbotbuildovich]

Retry command for Build#56349

please wait until all jobs are finished before running the slash command

/ci-repeat 1
tests/rptest/tests/cloud_storage_timing_stress_test.py::CloudStorageTimingStressTest.test_cloud_storage@{"cleanup_policy":"delete"}