Updates to use rust 1.85. Doesn't move to the 2024 edition, as that's a
fair bit more involved.
A nice side benefit is that the new rustc version seems to lead to a
slight reduction in binary size (at least on mac):
```
FILE SIZE
--------------
+4.3% +102Ki __DATA_CONST,__const
[NEW] +69.3Ki __TEXT,__literals
[NEW] +68.5Ki Rebase Info
+5.0% +39.9Ki __TEXT,__unwind_info
+57% +8.85Ki [__TEXT]
[NEW] +8.59Ki Lazy Binding Info
[NEW] +5.16Ki __TEXT,__stub_helper
[NEW] +3.58Ki Export Info
[NEW] +3.42Ki __DATA,__la_symbol_ptr
-0.1% -726 [12 Others]
-21.4% -3.10Ki [__DATA_CONST]
-95.8% -3.39Ki __DATA_CONST,__got
-20.9% -3.43Ki [__DATA]
-0.5% -4.52Ki Code Signature
-100.0% -11.6Ki [__LINKEDIT]
-1.0% -43.5Ki Symbol Table
-1.6% -44.0Ki __TEXT,__gcc_except_tab
-0.2% -48.1Ki __TEXT,__const
-3.3% -78.6Ki __TEXT,__eh_frame
-0.7% -320Ki __TEXT,__text
-1.5% -334Ki String Table
-0.5% -586Ki TOTAL
```
This is achieved by storing CJS export analysis ahead of time in the
executable, which should also improve the performance of `denort` by
this never being done anymore (I'm too lazy atm to bench this, but it
will be significant for some programs).
This slightly degrades the performance of CJS export analysis on
subsequent runs because I changed it to no longer cache in the DENO_DIR
with this PR (denort now properly has no idea about the DENO_DIR). We'll
have to change it to embed this data in the binary and that will also
allow us to get rid of swc in denort (will do that in a follow-up PR).
