freeResolution and syz are not thread-safe

Many operations rely on computing resolutions or syzygies, so naturally these two not being thread-safe makes lots of Macaulay2 un-parallelizable.

I came across this because I wanted to compute Ext of a single module against several different modules, which involves computing resolutions of the same module for each call to Ext. Here's a simpler example to try out:

S = kk[x,y,z];
M = truncate(5, S^1);
f = i -> schedule(freeResolution, M);
apply(2, f)
taskResult \ oo
class \ oo

Result:

i4 : apply(2, f)

o4 = {<<task, created>>, <<task, created>>}

o4 : List

i5 : /home/linuxbrew/.linuxbrew/Cellar/macaulay2/1.25.06_2/share/Macaulay2/Complexes/FreeResolutions.m2:91:17:(2):[3]: error: key not found in hash table:
        isComputable (of class Symbol)
/home/linuxbrew/.linuxbrew/Cellar/macaulay2/1.25.06_2/share/Macaulay2/Core/methods.m2:154:98:(1):[2]: --back trace--
/home/linuxbrew/.linuxbrew/Cellar/macaulay2/1.25.06_2/share/Macaulay2/Core/option.m2:17:14:(1):[1]: --back trace--
/home/linuxbrew/.linuxbrew/Cellar/macaulay2/1.25.06_2/share/Macaulay2/Core/option.m2:17:14:(1): --back trace--

       C-c C-c^C

i5 : taskResult \ oo

       21      35      15
o5 = {S   <-- S   <-- S  , }
                       
      0       1       2

o5 : List

i6 : class \ oo

o6 = {Complex, Nothing}

o6 : List

Similarly, running syz gens M several times in parallel causes crashes in threads:

i4 : apply(5, i -> schedule(syz, gens M))

o4 = {<<task, running>>, <<task, running>>, <<task, created>>, <<task, created>>, <<task, created>>}

o4 : List

i5 : -- SIGSEGV
-- SIGSEGV
-- SIGSEGV handler called a second time, aborting
*--* stack trace, pid: 
Process M2 exited abnormally with code 2

Reproduce the parallel freeResolution and syz examples, then inspect Complexes/FreeResolutions.m2:91 and the referenced Core/methods.m2 and Core/option.m2 paths. Determine why concurrent calls access shared state unsafely. Done means repeated parallel calls complete without errors or crashes and produce the same results as serial calls.