Determine the initial state for fragment parsing using the scripting flag of the context element (#37704)

When parsing a html fragment, the initial parser state depends on
whether or not scripting is enabled. So far we've used the scripting
flag of the parser, but that is wrong - the parser's scripting flag is
always false, because the fragment document has no browsing context.
Instead we should use the scripting flag of the context element.

Testing: A new web platform test passes

---------

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

Cargo.lock

@@ -1358,7 +1358,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
 dependencies = [
  "lazy_static",
- "windows-sys 0.48.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -3727,9 +3727,9 @@ dependencies = [
 
 [[package]]
 name = "html5ever"
-version = "0.32.1"
+version = "0.33.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a694fe8302828cfad7eae3f771ca0040b1aea123606ce34bbb4e13e5316ff407"
+checksum = "9d485f1d312f0938f1d8c175a115a1e9f357f8b63262a043b66ce11e1e48128b"
 dependencies = [
  "log",
  "mac",
@@ -4806,7 +4806,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "07033963ba89ebaf1584d767badaa2e8fcec21aedea6b8c0346d487d49c28667"
 dependencies = [
  "cfg-if",
- "windows-targets 0.48.5",
+ "windows-targets 0.52.6",
 ]
 
 [[package]]
@@ -9735,7 +9735,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.48.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]