Objects used within R6 methods not properly exported to multisession workers

**Describe the bug**

When using R6, future doesn't seem the objects to export within R6 methods.

**Reproduce example**

```r
library(R6)
library(future)
library(future.apply)
library(dplyr)

test_class <- R6::R6Class(
public = list(
df = data.frame(a = 1),
simulate = function() {
self$df %>% mutate(result = a * rnorm(nrow(self$df)))
},
run_many_times = function(times=10) {
results <- future_lapply(1:times, function(i) {
self$simulate()
}, future.seed = T)
return(results)
}
))

instance <- test_class$new()

plan(sequential)
instance$run_many_times(2)

plan(multicore)
instance$run_many_times(5)

plan(multisession)
instance$run_many_times(5)
```

The sequential and multicore runs work fine, but the multisession fails with:

```r
Error in self$df %>% mutate(result = a * rnorm(nrow(self$df))) :
could not find function "%>%"
```

**Expected behavior**

Running the instance$run_many_times returns a list of 5 elements, whether using the default backend, multicore, or multisession.

**Session information**

Please share your session information *after* the error has occurred so that we also see which packages and versions are involved;

```r
> sessionInfo()

R version 4.4.0 (2024-04-24)
Platform: aarch64-apple-darwin20
Running under: macOS Sonoma 14.7.6

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/lib/libRlapack.dylib; LAPACK version 3.12.0

Random number generation:
RNG: L'Ecuyer-CMRG
Normal: Inversion
Sample: Rejection

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: America/New_York
tzcode source: internal

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] dplyr_1.1.4 future.apply_1.11.2 future_1.58.0 R6_2.5.1

loaded via a namespace (and not attached):
[1] digest_0.6.37 codetools_0.2-20 tidyselect_1.2.1 magrittr_2.0.3 glue_1.7.0
[6] tibble_3.3.0 parallel_4.4.0 pkgconfig_2.0.3 generics_0.1.4 lifecycle_1.0.4
[11] cli_3.6.4 parallelly_1.45.1 vctrs_0.6.5 compiler_4.4.0 globals_0.18.0
[16] tools_4.4.0 listenv_0.9.1 pillar_1.10.2 rlang_1.1.5 jsonlite_1.9.1

> future::futureSessionInfo()
*** Package versions
future 1.58.0, parallelly 1.45.1, parallel 4.4.0, globals 0.18.0, listenv 0.9.1

*** Allocations
availableCores():
system /proc/self/status
10 10
availableWorkers():
$system
[1] "localhost" "localhost" "localhost" "localhost" "localhost" "localhost" "localhost" "localhost"
[9] "localhost" "localhost"

*** Settings
- future.plan=
- future.fork.multithreading.enable=
- future.globals.maxSize=
- future.globals.onReference=
- future.resolve.recursive=
- future.rng.onMisuse=
- future.wait.timeout=
- future.wait.interval=
- future.wait.alpha=
- future.startup.script=FALSE

*** Backends
Number of workers: 1
List of future strategies:
1. sequential:
- args: function (..., gc = FALSE, earlySignal = FALSE, envir = parent.frame(), workers = "")
- tweaked: FALSE
- call: plan(sequential)

*** Basic tests
Main R session details:
pid r sysname release
1 2480 4.4.0 Darwin 23.6.0
version
1 Darwin Kernel Version 23.6.0: Thu Apr 24 20:29:18 PDT 2025; root:xnu-10063.141.1.705.2~1/RELEASE_ARM64_T6000
nodename machine login user effective_user
1 host001 arm64 user002 user001 user001
Worker R session details:
worker pid r sysname release
1 1 2480 4.4.0 Darwin 23.6.0
version
1 Darwin Kernel Version 23.6.0: Thu Apr 24 20:29:18 PDT 2025; root:xnu-10063.141.1.705.2~1/RELEASE_ARM64_T6000
nodename machine login user effective_user
1 host001 arm64 user002 user001 user001
Number of unique worker PIDs: 1 (as expected)
```