chore(deps): bump subby to 0.3.30 and pycaption to 2.2.22

- subby pin 1ea6a52 -> a057280: improved missing-line-split handling, duplicate frontal hyphen removal, UTF-8 without BOM output, Python <=3.11 syntax fix
- pycaption 2.2.20 -> 2.2.22: SCC-only fixes, no impact on our SRT/DFXP/WebVTT usage
- pytest: filter third-party warnings (aiohttp NotAppKeyWarning required by pywidevine/pyplayready string app keys, pycaption bs4 deprecations)

pyproject.toml

@@ -111,6 +111,9 @@ filterwarnings = [
     "ignore::DeprecationWarning:click.*",
     "ignore::DeprecationWarning:unshackle.core.services",
     "ignore::DeprecationWarning:ast",
+    "ignore::aiohttp.web_exceptions.NotAppKeyWarning",
+    "ignore::DeprecationWarning:pycaption.*",
+    "ignore::bs4.XMLParsedAsHTMLWarning",
 ]
 addopts = "-ra --strict-markers"
 
@@ -154,4 +157,4 @@ skips = [
 
 [tool.uv.sources]
 unshackle = { workspace = true }
-subby = { git = "https://github.com/vevv/subby.git", rev = "1ea6a52028c5bea8177c8abc91716d74e4d097e1" }
+subby = { git = "https://github.com/vevv/subby.git", rev = "a057280f31acd3a0ba5c6dc69eaefbb88aea974e" }