ams: bump version, add enum support for 20.4.0

exo: fix register access tables to page start

build: portability fixes ...

- Invoke Python scripts with `python3` if `python` is not available.

  Despite SciresM preferring Python 2, the scripts used in the build all
  worked in Python 3 already, so this is just a Makefile change.

- Export `MAKE` to work around a GNU bug.

  See the comment for details.

- `rmdir --ignore-fail-on-non-empty` -> `rmdir 2>/dev/null`

  macOS `rmdir` doesn't support `--ignore-fail-on-non-empty`.

  This is a slight downgrade in functionality, because now we ignore all
  errors from `rmdir` rather than just 'Directory not empty'.  I could
  have avoided this with a more complicated fix, but the benefit strikes
  me as not worth the complexity.  Let me know if you disagree.

- Append `$(DEVKITPRO)/tools/bin/` to `$PATH` when invoking
  `build_romfs`.

  This avoids the need to add devkitPro directories to `$PATH` when
  building Atmosphere.

  If you already have `build_romfs` in your PATH, then that will still
  take precedence.  (This seemed like the nicer option, though I don't
  have strong opinions.)

nanovg: disable some compiler warnings ...

Disable all warnings seen on devkitA64 GCC 15.1.0:

- Several false-positive `-Wmisleading-indentation` warnings (the
  indentation is not actually misleading)

- One `-Wuse-after-free` warning, which looks alarming and represents
  very dubious design, but is ultimately harmless (a freed pointer is
  passed to a function that doesn't use it).

- Some `-Wunused-function` warnings in `simd/neon.h`

daybreak: fix strncpy compiler warning ...

GCC warned that the output string would not be nul-terminated if the
input string was too long.  Fix this by subtracting 1 from the size
argument, as is done for other `strncpy` calls in the file.  (It would
probably be better to avoid `strncpy` entirely, but this is just a
simple fix.)

haze: fix duplicate-macro warnings ...

haze was including both `<switch.h>` and `vapours/types.hpp` which both
define `R_SUCCEEDED` and `R_FAILED`, producing compiler warnings.

The intent is that `vapours/types.hpp` only gets included when targeting
not-Switch and/or not-EL0.  But the check didn't account for
Troposphère.  Fix that.

git subrepo push libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "bc7a0fc11"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "bc7a0fc11"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

ams: bump version, support 20.3.0

fs.mitm: steal some heap when building romfs for kotor2 (closes #2564)

git subrepo push libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "af10bca1b"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "af10bca1b"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

ams: bump version, add 1.9.2 changelog

git subrepo push libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "4e3615355"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "4e3615355"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

ams: add enum version support for 20.1.x/20.2.0

loader: add usb 3.0 enable patches for 20.1.0 (#2556) ...

* loader: add usb 3.0 enable patches for 20.1.0

git subrepo push libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "0f72b2ceb"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "0f72b2ceb"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

docs: add basic changelog for 1.9.1

Clarify that code type 0xC4 uses a 64-bit value in cheats.md by formatting the key values as such ...

Changes the formatting of the key values at `Code Type 0xC4: Begin Extended Keypress Conditional Block` in cheats.md so that it is perfectly clear that those values are 64-bit values rather than 32-bit or 28-bit like `Code Type 0x8: Begin Keypress Conditional Block`, and also for the fact that the formatting matches the rest of the document and is thus cleaner.

git subrepo push emummc ...

subrepo:
  subdir:   "emummc"
  merged:   "a8e5f1a18"
upstream:
  origin:   "https://github.com/m4xw/emummc"
  branch:   "develop"
  commit:   "a8e5f1a18"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

emummc: note 20.1.0 support in README

kern: move spendsgir static assert

fusee/emummc: add support for FS 20.1.0

erpt: update IDs for 20.1.0

kern: save/restore spendsgir in KInterruptController::Save/RestoreCoreLocal

kern: wait 100us after synchronizing cores before saving interrupt state on sleep

kern: use KLightLock for KCoreBarrierInterruptHandler

Add version enums for 20.1.0

docs: add banner to readme

git subrepo push libraries ...

subrepo:
  subdir:   "libraries"
  merged:   "9e8cbe3fa"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "9e8cbe3fa"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

svc: bump supported kernel version

git subrepo push emummc ...

subrepo:
  subdir:   "emummc"
  merged:   "7522f1f60"
upstream:
  origin:   "https://github.com/m4xw/emummc"
  branch:   "develop"
  commit:   "7522f1f60"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"